®
®
Using EMC VNX Storage with
VMware vSphere
Version 4.0
TechBook
P/N H8229
REV 05
Copyright © 2015 EMC Corporation. All rights reserved. Published in the USA.
Published January 2015
EMC believes the information in this publication is accurate as of its publication date. The information is subject to change without
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For the most up-to-date regulatory document for your product line, go to EMC Online Support (https://support.emc.com).
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Using EMC VNX Storage with VMware vSphere TechBook
CONTENTS
Preface
Chapter 1
Configuring VMware vSphere on VNX Storage
Technology overview ................................................................................... 18
EMC VNX family..................................................................................... 18
FLASH 1st.............................................................................................. 18
MCx multicore optimization................................................................... 19
VNX performance .................................................................................. 20
VNX compounded efficiencies ............................................................... 20
VNX protection ...................................................................................... 20
File system management....................................................................... 21
VNX availability ..................................................................................... 21
VNX family software .............................................................................. 22
Management tools ...................................................................................... 23
EMC Unisphere ..................................................................................... 23
EMC VSI for VMware vSphere................................................................. 25
VMware vStorage APIs for Array Integration ........................................... 29
VMware vStorage APIs for Storage Awareness ....................................... 29
Installing VMware vSphere on VNX .............................................................. 29
Installing the ESXi hypervisor ................................................................ 31
Installing vSphere ................................................................................. 31
Configuring vSphere with VNX ..................................................................... 35
Host connectivity .................................................................................. 35
Configuring the Network........................................................................ 41
iSCSI connectivity options for ESXi and VNX .......................................... 43
Provisioning VNX storage for vSphere.......................................................... 51
Creating an NFS datastore using VSI...................................................... 51
Provisioning block storage for VMFS datastores and RDM volumes........ 54
Unified storage considerations.................................................................... 56
Datastore virtual machine density ......................................................... 57
Best practices for extending a datastore................................................ 57
Solid state volumes for VNX OE for File .................................................. 58
General recommendations for storage sizing and configuration............. 58
Storage multipathing ............................................................................ 59
vSphere storage considerations .................................................................. 70
Dead space reclamation (Unmap) ......................................................... 70
VMFS-5 ................................................................................................. 72
vStorage API for Storage Awareness ...................................................... 80
Network considerations .............................................................................. 89
Network I/O Control .............................................................................. 89
Virtual machine considerations ................................................................... 91
Virtual machine disk partition alignment ............................................... 91
Virtual machines resiliency over NFS ..................................................... 98
Monitoring and managing storage............................................................... 99
Monitoring datastores using vCenter ..................................................... 99
Configuring VNX file-system storage usage notification ....................... 103
Thinly provisioned storage .................................................................. 108
LUN compression ................................................................................ 115
File deduplication and compression.................................................... 116
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Contents
VNX storage options.................................................................................. 117
VNX supported disk types ................................................................... 118
Disk grouping...................................................................................... 118
Chapter 2
Cloning Virtual Machines
Introduction.............................................................................................. 128
Using EMC VNX cloning technologies ........................................................ 128
Replicating virtual machines with VNX SnapView ................................ 129
Replicating virtual machines on VMFS datastores with SnapView clones ....
129
Replicating virtual machines on VMFS datastores with SnapView Snapshot
131
ESXi volume signatures ....................................................................... 132
Replicating virtual machines with SnapView clones of RDM LUNs ........ 134
Cloning virtual machines on VNX NFS datastores with VNX SnapSure .. 135
Cloning virtual machines with native vCenter cloning and VAAI ........... 136
Cloning individual virtual machines on NFS datastores........................ 137
Summary .................................................................................................. 138
Chapter 3
Backup and Recovery Options
Introduction..............................................................................................
Virtual machine data consistency ..............................................................
VNX native backup and recovery options...................................................
File system logical backup and restore using VNX SnapSure................
Physical backup and restore using VNX File Replicator ........................
Snapshot backup and recovery of a VMFS datastore..................................
Backup and recovery of RDM volumes .......................................................
AppSync .............................................................................................
VSI AppSync Management ..................................................................
Replication Manager .................................................................................
Backup and recovery of a VMFS with VNX Advanced Snaps........................
vStorage APIs for Data Protection ..............................................................
Backup and recovery using VMware Data Protection..................................
Local data protection with vSphere Data Protection.............................
Installing VDP......................................................................................
Creating a backup job .........................................................................
Local Data Protection with vSphere Data Protection Advanced ............
Configuring replication sessions .........................................................
VDP Emergency Restore.......................................................................
Backup and recovery using Avamar ...........................................................
Architectural view of the Avamar environment .....................................
Backing up data using Avamar ............................................................
Recovering data using Avamar ............................................................
Backup and recovery using NetWorker.......................................................
VNX storage devices for NetWorker......................................................
Using NetWorker to backup and restore VNX NAS file system NDMP ....
Summary ..................................................................................................
Chapter 4
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Using VMware vSphere in Data Restart Solutions
Introduction.............................................................................................. 196
Definitions and Considerations ........................................................... 196
Design considerations for DR and data restart ..................................... 197
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Contents
Testing the solution.............................................................................
Geographically distributed vSphere environments ..............................
EMC remote replication technology overview.............................................
EMC Replicator....................................................................................
EMC MirrorView...................................................................................
Failover MirrorView LUNs to a remote site using CLI .............................
EMC RecoverPoint ...............................................................................
RDM volume replication ............................................................................
Configuring remote sites for vSphere virtual machines with RDM.........
Starting virtual machines at a remote site after a disaster....................
Configuring remote sites for virtual machines using VMFS ...................
EMC Replication Manager..........................................................................
Automating site failover with SRM and VNX ...............................................
SRM testing.........................................................................................
EMC Storage Replication Adapter ........................................................
SRM protection groups at the protected site ........................................
SRM recovery plan...............................................................................
Summary ..................................................................................................
Chapter 5
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Data Vaulting and Migration
Introduction.............................................................................................. 228
Using SAN Copy with VMware file systems................................................. 228
Using SAN Copy with RDM virtual disks ..................................................... 229
Using SAN Copy for data vaulting .............................................................. 229
Using SAN Copy for data vaulting of VMware file systems .................... 230
Using SAN Copy for data vaulting of virtual machines configured with RDMs
233
Importing Storage into the remote environment ........................................ 234
Configuring remote sites for virtual machines using VMFS ................... 234
Configuring remote sites for vSphere virtual machines with RDM......... 234
Using SAN Copy to migrate data to VNX arrays ........................................... 235
Migrating devices used as RDM........................................................... 237
Summary .................................................................................................. 237
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Contents
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Using EMC VNX Storage with VMware vSphere TechBook
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EMC Unisphere interface .............................................................................................
Viewing LUN properties ...............................................................................................
VSI Feature Manager ...................................................................................................
Unified Storage Access Control workflow.....................................................................
Storage Viewer NFS datastore details ..........................................................................
Storage Viewer VNX block storage details....................................................................
Configuration workflow ...............................................................................................
Unisphere LUN assignment for ESXi boot device..........................................................
iBFT interface for VNX target configuration...................................................................
VNX iSCSI port management interface .........................................................................
VNX storage with VMware vSphere ..............................................................................
ESXi topology with FC/FCoE/iSCSI/NFS connectivity to VNX .........................................
VNX configuration of host initiator...............................................................................
VMkernel port configuration ........................................................................................
VNX multiple subnet iSCSI target port addressing .......................................................
iSCSI Software initiator configuration in vSphere 5 ......................................................
Topology diagram for multiple-subnet iSCSI configuration...........................................
Recommended configuration for VNX iSCSI targets......................................................
Disable Delayed Acknowledgement setting on storage adapter ...................................
File storage provisioning with Unified Storage Management ........................................
Creating a new NFS datastore with Unified Storage Management ................................
File storage provisioning with Unified Storage Management ........................................
Creating a new VMFS datastore with Unified Storage Management..............................
LUN ownership............................................................................................................
LUN trespass...............................................................................................................
Stripe locking service ..................................................................................................
VMkernel pluggable storage architecture ....................................................................
Esxcli command output...............................................................................................
VSI Path Management feature .....................................................................................
Storage Viewer LUNs view ...........................................................................................
Elements of a multipathing configuration for NFS ........................................................
Unisphere interface.....................................................................................................
Data Mover link aggregation for NFS server..................................................................
vSphere networking configuration...............................................................................
VMkernel Properties window .......................................................................................
Virtual machine configured on a Thick LUN..................................................................
Virtual machine migrated to a thin LUN .......................................................................
Create File System.......................................................................................................
Plug-in installation ......................................................................................................
NFS Hardware Accelerate datastore property ...............................................................
Vmkfstools disk utilization option ...............................................................................
SDRS datastore cluster................................................................................................
SDRS advanced policy configuration ...........................................................................
SDRS I/O metric enablement setting ...........................................................................
VASA datastore storage capability of VNX Flash drive LUN ...........................................
Storage profile assignment .........................................................................................
Compatibility/incompatibility with SAS Fibre storage profile .......................................
Enabling virtual machine storage profiles....................................................................
Associating datastores with a user-defined storage profile ..........................................
Associating the virtual machine with a user defined storage capability........................
VASA configuration .....................................................................................................
Virtual disk shares configuration .................................................................................
NFS SIOC congestion window ......................................................................................
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Network Resource Allocation interface ........................................................................ 89
vSphere 5 Datastore removal wizard ........................................................................... 90
Select the disk ............................................................................................................ 92
Guest disk alignment validation .................................................................................. 93
NTFS data partition alignment (wmic command).......................................................... 93
Output of 1 MB aligned Linux partition ........................................................................ 94
Output for an unaligned Linux partition (starting sector 63)......................................... 94
Host Cache configuration on VNX EFD storage ............................................................. 95
Enable NPIV for a virtual machine after adding an RDM volume ................................... 97
Manually register virtual machine (virtual WWN) initiator records ................................ 97
Data Alarm Settings-Actions window ......................................................................... 100
Storage Viewer\Datastores window-VMFS datastore.................................................. 101
Adjustable percent full threshold for the storage pool ............................................... 102
Create Storage Usage Notification window ................................................................ 103
User-defined storage usage notifications .................................................................. 104
User-defined storage projection notifications ............................................................ 105
VNX Monitoring and Reporting: Capacity Planning Report .......................................... 105
VNX Monitoring and Reporting - Performance report .................................................. 106
vCenter Operations Manager Dashboard ................................................................... 107
vCenter Operations Manager: VNX Storage Analytics ................................................. 108
Thick or ZeroedThick virtual disk allocation ............................................................... 111
Thin virtual disk allocation ........................................................................................ 111
Virtual machine disk creation wizard ......................................................................... 112
Virtual machine out-of-space error message.............................................................. 113
File system High Water Mark in the Unified Storage Management feature of VSI ........ 114
Provisioning policy for an NFS virtual machine virtual disk......................................... 115
LUN compression property configuration................................................................... 115
VNX FAST VP reporting and management interface .................................................... 122
Disk Provisioning Wizard........................................................................................... 125
Unisphere clone LUN management............................................................................ 130
Performing a consistent clone fracture operation....................................................... 131
Creating a SnapView session to create a copy of a VMware file system ...................... 132
Device signature assignment .................................................................................... 133
Selecting virtual machine configuration files in the datastore browser....................... 134
Adding the new virtual machine to the ESXi host inventory........................................ 135
Creating a writeable NAS datastore checkpoint ......................................................... 136
Cloned NFS datastore in vSphere .............................................................................. 138
Viewing ChildFsRoot parameter properties in Unisphere............................................ 144
Snapshot Configuration Wizard ................................................................................. 146
Snapshot Configuration Wizard (continued) .............................................................. 147
Adding a VNX Storage System to AppSync ................................................................. 149
Editing Service Plan settings ..................................................................................... 150
Subscribing to a Service Plan .................................................................................... 150
Overview of protected and unprotected datastores ................................................... 150
VSI AppSync registration ........................................................................................... 151
Protect datastore....................................................................................................... 152
Using VSI AppSync Feature to Configure datastore protection.................................... 152
Subscribe Datastores to a AppSync Service Plan ....................................................... 153
Resignaturing a copy of an existing datastore............................................................ 153
Using vCenter to manually copy a virtual machine ..................................................... 154
Replication Manager Job Wizard ................................................................................ 155
Viewing Replica Properties in Replication Manager.................................................... 156
Restoring a virtual machine using Replication Manager ............................................. 156
Using EMC VNX Storage with VMware vSphere TechBook
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Viewing a read-only copy of the datastore in vSphere Client ......................................
Advanced Snapshot Basic Configuration ...................................................................
Viewing Snapshot Mount Points................................................................................
Using the Snapshot Mount Point Configuration Wizard..............................................
Creating a snapshot consistency group .....................................................................
Creating a consistency group snapshot .....................................................................
Attaching a consistency group snapshot ...................................................................
VADP flow diagram....................................................................................................
VMware Data Recovery ..............................................................................................
vSphere Data Protection............................................................................................
Allocation of virtual disks on one or more datastores ................................................
vSphere Getting Started menu...................................................................................
Backup with selected virtual disks ............................................................................
VDP backup schedule ...............................................................................................
Retention policy form ................................................................................................
License Key window ..................................................................................................
In-guest agents .........................................................................................................
Creating a new replication job ...................................................................................
Replication backup schedule ....................................................................................
Avamar replication target ..........................................................................................
Scheduling the replication session............................................................................
Retention policy for the Avamar target .......................................................................
Restore of a powered on virtual machine ...................................................................
Restoring a virtual machine .......................................................................................
Restoring a backup with VDP.....................................................................................
Setting Restore Options ............................................................................................
Selecting the restore destination...............................................................................
Set Restore Options dialog box .................................................................................
Selecting an individual disk ......................................................................................
Setting the Restore Options for restoring an individual disk.......................................
Selecting the restore destination...............................................................................
A virtual disk after a restore.......................................................................................
Login options for the vSphere Data Protection Restore Client.....................................
Selecting individual disks from which to restore files ................................................
Restoring selected files or directories........................................................................
Monitor Restores menu .............................................................................................
Performing a VDP Emergency Restore of a virtual machine.........................................
Performing an emergency restore to an individual ESXi host......................................
Sample Avamar environment ....................................................................................
Sample proxy configuration.......................................................................................
Avamar backup management configuration options ..................................................
Avamar virtual machine image restore.......................................................................
Avamar browse tree ..................................................................................................
NetWorker-virtualization topology view .....................................................................
Viewing a VADP snapshot..........................................................................................
NetWorker configuration settings for VADP ................................................................
NDMP recovery using NetWorker ...............................................................................
Backup with integrated checkpoint ...........................................................................
Data replication wizard .............................................................................................
Replication wizard (continued) ..................................................................................
Preserving dependent-write consistency with MirrorView consistency groups............
EMC Unisphere interface ...........................................................................................
Enable MirrorView between VNX systems ..................................................................
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MirrorView Wizard - select source LUNs .....................................................................
MirrorView Wizard - select remote storge...................................................................
Promote mirrored LUN ...............................................................................................
Business continuity solution using MirrorView/S in a virtual infrastructure with VMFS
Synchronize MirrorView LUNs....................................................................................
RecoverPoint architecture overview ...........................................................................
Disabling VAAI support on an ESXi host.....................................................................
RM protection for NFS datastores and virtual machines .............................................
Using the vSphere client to register a virtual machine with ESXi ................................
SRM recovery plan summary .....................................................................................
VMware vCenter SRM configuration ...........................................................................
Creating an SRM protection group .............................................................................
Testing the recovery plan ..........................................................................................
Recovery plan Cleanup ..............................................................................................
SRM recovery plan with EMC MirrorView ....................................................................
SRM reprotect ...........................................................................................................
Data vaulting with Incremental SAN Copy ..................................................................
Using Unisphere or Storage Viewer to identify source LUNs .......................................
Creating an Incremental SAN Copy session................................................................
Creating an Incremental SAN Copy session (continued).............................................
Creating a SAN Copy session to migrate data to a VNX...............................................
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TABLES
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VNX family software .................................................................................................... 22
Multiple Subnet Configuration IPs/IQNs ...................................................................... 47
Recommended Native Multipathing Plug-in path selection .......................................... 64
NFS VAAI features........................................................................................................ 74
Supported SDRS LUN configurations ........................................................................... 80
VASA storage capability mapping to VNX LUNs............................................................ 81
VNX OE for Block 5.32 storage capability mapping to VNX LUNs .................................. 82
SIOC congestion windows ........................................................................................... 88
VNX Connector metrics.............................................................................................. 107
Command line descriptions for vSphere 5.5,vSphere 5, and vSphere 4 ..................... 109
Virtual machine disk allocation policies .................................................................... 109
Disk types supported by VNX..................................................................................... 118
Pool capabilities ....................................................................................................... 119
VNX RAID options ...................................................................................................... 119
Thin LUNs versus Thick LUNs..................................................................................... 124
VNX-based technologies for virtual machine cloning ................................................. 139
VDP and VDPZ feature comparison ............................................................................ 166
Capacities for VDP deployments................................................................................ 168
vSphere Data Protection tabs .................................................................................... 170
Resources for VDPA-Deployments ............................................................................. 173
Backup and recovery options .................................................................................... 194
EMC replication options for VMware environments .................................................... 198
VNX MirrorView limits................................................................................................ 202
Minimum revision levels for VAAI support with VNX RecoverPoint splitter .................. 211
EMC RecoverPoint feature support............................................................................. 212
VNX to virtual machine RDM ...................................................................................... 213
Data replication solutions ......................................................................................... 225
Using EMC VNX Storage with VMware vSphere TechBook
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Tableses
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Using EMC VNX Storage with VMware vSphere TechBook
PREFACE
As part of an effort to improve its product lines, EMC periodically releases revisions of its
software and hardware. Therefore, some functions described in this document might not
be supported by all versions of the software or hardware currently in use. The product
release notes provide the most up-to-date information on product features.
Contact your EMC technical support professional if a product does not function properly or
does not function as described in this document.
Note: This document was accurate at publication time. Go to EMC Online Support
(https://support.emc.com) to ensure that you are using the latest version of this
document.
Purpose
This document describes how VMware vSphere works with the EMC VNX family of storage
systems. Although this document focuses on VNX2 storage, much of the content also
applies when using vSphere with EMC Celerra or EMC CLARiiON storage systems.
Audience
This document is intended for storage administrators, system administrators, and VMware
administrators. Individuals involved in acquiring, managing, or operating EMC VNX
storage arrays and host devices and readers with knowledge of the following topics will
benefit from this document:
◆
EMC VNX family
◆
EMC Unisphere
◆
EMC irtual Storage Integrator (VSI) for VMware vSphere
◆
VMware vSphere
Related documentation
The following EMC publications provide additional information:
◆
EMC VSI for VMware vSphere Web Client: Product Guide
◆
EMC VSI for VMware vSphere Web Client: Release Notes
◆
EMC VSI for VMware vSphere: Unified Storage Management Product Guide
◆
EMC VSI for VMware vSphere: Unified Storage Management Release Notes
◆
EMC VSI for VMware vSphere: Storage Management Product Guide
◆
EMC VSI for VMware vSphere: Storage Management Release Notes
◆
EMC VSI for VMware vSphere: Path Management Product Guide
◆
EMC VSI for VMware vSphere: Path Management Release Notes
◆
EMC VSI for VMware vSphere: AppSync Management Product Guide
◆
EMC VSI for VMware vSphere: AppSync Management Release Notes
Using EMC VNX Storage with VMware vSphere TechBook
13
Preface
◆
EMC VSI for VMware vSphere: EMC RecoverPoint Management Product Guide
◆
EMC VSI for VMware vSphere: EMC RecoverPoint Management Release Notes
◆
EMC VSI for VMware vSphere: SRA Utilities Product Guide
◆
EMC VSI for VMware vSphere: SRA Utilities Release Notes
The following VMware websites provide more information about VMware products:
◆
http://www.vmware.com/products/
◆
http://www.vmware.com/support/pubs/vs_pubs.html
Conventions used in this document
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NOTICE is used to address practices not related to personal injury.
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Use for user input.
Using EMC VNX Storage with VMware vSphere TechBook
Preface
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Product information — For documentation, release notes, software updates, or
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https://support.emc.com
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Using EMC VNX Storage with VMware vSphere TechBook
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Preface
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Using EMC VNX Storage with VMware vSphere TechBook
CHAPTER 1
Configuring VMware vSphere on VNX Storage
This chapter presents the following topics:
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Technology overview ............................................................................................... 18
Management tools .................................................................................................. 23
Installing VMware vSphere on VNX .......................................................................... 29
Configuring vSphere with VNX ................................................................................. 35
Provisioning VNX storage for vSphere...................................................................... 51
Unified storage considerations................................................................................ 56
vSphere storage considerations .............................................................................. 70
Network considerations .......................................................................................... 89
Virtual machine considerations ............................................................................... 91
Monitoring and managing storage........................................................................... 99
VNX storage options.............................................................................................. 117
Configuring VMware vSphere on VNX Storage
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Configuring VMware vSphere on VNX Storage
Technology overview
This section provides information about the technologies associated with the next
generation of EMC® VNX® storage systems in the context of a VMware vSphere virtualized
environment.
EMC VNX family
EMC VNX unified storage systems deliver platform efficiency and innovation with
enterprise capabilities for file, block, and object storage in a scalable, easy-to-use,
high-performance solution. The VNX family of storage systems is ideal for mixed
workloads in virtual environments. It combines extremely powerful and flexible hardware
with advanced multicore optimization, management, and data protection software to
meet the most demanding needs of today's enterprises.
VNX is multiprotocol compatible (file, block, object), giving you the flexibility to deploy
expandable, future-ready storage. The powerful controller architecture of VNX storage
helps ensure that you won't run out of storage processor power for transactions or
bandwidth during the service life of the storage system. Capacity- and
performance-scaling capabilities enable on-demand capacity management in
combination with built-in capacity efficiency features such as thin provisioning,
block-level deduplication, EMC Fully Automated Storage Tiering (FAST™) technology, and
compression.
FLASH 1st
The general availability of NAND flash storage media has fundamentally changed storage
system design and IT best practices. Flash drive storage delivers the highest I/O
performance with the lowest latency of any storage media. The need to store all active
data on flash drives is driven by the multicore/multisocket designs of modern servers.
Such servers typically run multiple virtualized server instances—anywhere from 10 to 100
virtual machines. In addition, a VNX system typically serves 10 to 100 or more servers.
Therefore, a single VNX system must be able to meet the transactional demands of several
thousand virtual machines. Flash is the only way to accomplish this without using up to a
quarter million 15K disk drives. Flash memory is higher performing and delivers lower
transaction costs.
EMC's FLASH 1st strategy takes advantage of FAST technology. As application workloads
shift to new and highly active data, less active data is identified and automatically moved
from flash to lower-cost, high-capacity disks. FAST technology ensures that adequate flash
capacity is available for the active portion of all the workloads on the VNX system.
The FAST Suite consists of FAST-VP and FAST Cache. While FAST Cache works to handle any
transitory exceptions, FAST-VP moves data to the appropriate tier based on persistent
trending. FAST-VP moves slices between tiers over a broader sample time. FAST Cache
caches any data that is not already on a Flash drive onto a separate set of flash drives. The
FAST Suite enables the servicing of workloads requiring a large number of 15K drives with
a mix of tiers and lower drive count.
Typically a small amount of flash memory can service a high percentage of the overall
IOPS. The target is to serve at least 80 percent of the IOPS, with flash memory making up
about 5 percent of total storage capacity. For overall value in flash performance, hybrid
arrays are the best platform choice.
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MCx multicore optimization
The advent of flash technology has completely changed the requirements of mid-range
storage systems. EMC redesigned the mid-range storage platform to efficiently optimize
multicore CPUs and provide the highest-performing storage system at the lowest cost. The
EMC MCx™ multicore optimization architecture, which comprises Multicore Cache,
Multicore FAST Cache, and Multicore RAID, provides the market-leading foundation of
mid-range storage for the next decade.
MCx distributes all VNX data services across all cores. MCx dramatically improves file
performance for transactional applications, such as databases, and virtual machines over
network-attached storage (NAS).
The advances in the VNX platform ensure that cache management and back-end RAID
management processes take full advantage of multicore CPUs. This allows cache and
back-end processing software to scale in a linear fashion, enabling EMC to take full
advantage of the power of the latest multicore CPUs. The VNX has a scaling factor of 97
percent, providing the ability to add cores as needed for future scaling.
Multicore Cache
The cache is the most valuable storage asset in the storage subsystem, and its efficient
use is essential to the overall efficiency of a platform handling variable and changing
workloads. With Multicore Cache, the cache engine is modularized to take advantage of all
the cores available in the system, enabling the VNX storage to scale seamlessly.
In addition, Multicore Cache eliminates the need to manually reserve separate space for
read and write cache, so no management overhead is required to ensure that the cache is
working most effectively.
The VNX system uses dynamic and adaptive cache management through advanced
caching algorithms to optimally handle varying sequential and random read and write
workloads. Highly intelligent write flushing tracks arrival rates as well as the ability of the
back end-disks or SSDs to write the data out of cache. It provides adaptive queueing to
throttle write rates in place of forced flush situations. All cache pages are dynamically
assigned depending on the needs of the system. New pages are allocated immediately, as
needed, for reads, writes, thin metadata, and so forth, which ensures that the system
resources are constantly being tuned to match the changing workloads.
Multicore RAID
The MCx architecture improves the handling of I/O to the permanent back-end storage
(HDDs and SSDs). The significant performance improvements in the VNX come from the
modularization of the back-end data management processing, which allows it to
seamlessly scale across all processors.
In addition, with RAID processing that is highly mature, the VNX system delivers improved
flexibility, ease of use, and reliability.
Technology overview
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Configuring VMware vSphere on VNX Storage
VNX performance
The VNX with the MCx architecture takes advantage of the FLASH 1st strategy and provides
unprecedented overall performance, optimizing transactional performance, bandwidth
performance, and capacity efficiency. Compared to the previous generation, the VNX
provides:
◆
Up to 4 times more file transactions—best in the industry compared to dual controller
arrays
◆
Improved file performance for transactional applications (for example, Exchange on
VMware over NFS) by up to 3 times with 60 percent better response time
◆
Up to 4 times more Oracle and SQL OLTP transactions
◆
Support for up to 4 times more virtual machines—a greater than 3 times improvement
◆
Up to 3 times more bandwidth for Oracle and SQL data warehousing
VNX compounded efficiencies
Compounded efficiencies provide a way to easily save money by combining VNX
out-of-band block-based deduplication and improved FAST Suite tiering technologies to
dramatically lower the costs of the flash tier and reduce the cost per gigabyte. VNX
provides compounded efficiencies through the following technologies:
◆
FAST Suite improvements—The VNX series increases FAST Cache capacities, delivers 4
times better FAST VP granularity (256 MB versus 1 GB), and supports new FAST VP
SSDs based on enterprise multilevel cell (eMLC) technology to lower the cost per
gigabyte.
◆
Fixed block deduplication—While only a few flash drives—typically between 1 percent
and 5 percent of total capacity—are needed to improve performance and lower costs,
you can further reduce capacity with deduplication, which is ideal for virtual machine
environments.
VNX protection
VNX storage systems provide enhanced data protection through the following improved
technologies:
◆
Online file migrations—The VNX Virtual Data Mover (VDM) technology has been
enhanced to perform automated, highspeed file system migrations between systems.
◆
Improved application uptime—VNX active/active for block improves application
uptime by allowing clients to access a classic LUN (non-pooled LUN) simultaneously
through both storage processors for improved reliability, ease of management, and
improved performance.
◆
20
More affordable remote replication—EMC RecoverPoint® 4.0 enhancements include
synchronous replication over IP, failover to any point in time with VMware SRM, and a
new virtual EMC RecoverPoint appliance to reduce acquisition cost.
Using EMC VNX Storage with VMware vSphere TechBook
Configuring VMware vSphere on VNX Storage
File system management
File system management includes:
◆
Transactional NAS—Encompasses workloads such as server virtualization and
databases, which have traditionally been directed toward block storage.
◆
Capacity NAS—Designed for large-capacity file data (“big data”) and delivers high
aggregate performance. It is scaled out NAS and is characterized by providing a very
large single namespace.
◆
Traditional NAS—Typically handles smaller file stores but still needs comprehensive
features such as deduplication, snapshots, quotas, and WORM.
VNX availability
This section describes the asymmetric active/active—also known as asymmetrical logical
unit access (ALUA)—and symmetric active/active access models.
Asymmetric active/active
In the first-generation VNX models, EMC implemented an asymmetric access model where
a single path is optimized and all I/O is sent down this path unless an issue
(failure/congestion) occurs, after which the I/O is sent via the secondary path to the
backup storage processor (SP). In the ALUA model a single SP “owns” the host LUN and
any access from the secondary path is serviced via the inter-SP links from the owning SP to
the secondary SP. If the failed path to the owning SP is offline for a period of time, the LUN
is trespassed and the secondary SP becomes the owning SP. Although this is a
satisfactory access model, the host still uses a single storage controller to access the LUN
unless the ESXi host multipath settings have been changed.
Symmetric active/active
With the VNX systems and the introduction of MCx, EMC offers the first phase of an
active/active access model that allows a host’s multipathing software to access the LUN in
a balanced manner across both SPs.
This design eliminates the concept of LUN ownership and redirection throughout the
stack. It provides reduced failover times and reduces data outages caused by trespass
storms, resulting in significant performance improvement. In the past, due to CPU
bottlenecks, the systems could not take advantage of the back-end resources. With
symmetric active/active, access to the remaining back-end resources is available through
the peer SP. This model allows clients to access a classic LUN (non-pooled) through both
SPs simultaneously for improved reliability, ease-of management, and improved
performance.
Technology overview
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Configuring VMware vSphere on VNX Storage
VNX family software
Table 1 describes the contents of the VNX software components.
Table 1 VNX family software
Software
Contents
Unisphere®
Management Suite
(required)
Unisphere, Unisphere Remote, Unisphere Analyzer, Unisphere Quality
of Service Manager (QoS), VNX Monitoring and Reporting (storage-only
version)
Operating Environment
(required)
All protocols, thin provisioning, compression, deduplication, SAN Copy,
and ODX Enabler
EMC Storage Analytics
for VNX
VNX version of VMware vCenter Operations Manager, EMC Adapter for
VNX
FAST Suite
FAST CAche and FAST VP
Security and
Compliance Suite
VNX Host Encryption, File Level Retention, Common Event Enabler (CEE)
Anti-Virus Agent, and Event Publishing Agent
Local Protection Suite
SnapSure, SnapView, VNX Snapshots, EMC RecoverPoint SE CDP
Remote Protection
Suite
Replicator, MrrrorView A/S, RecoverPoint SE CRR
Application Protection
Suite
AppSync, Replication Manager
The VNX software components are described as follows:
22
◆
Unisphere Management Suite—Extends Unisphere's easy-to-use interface to include
VNX monitoring and reporting for validating performance and anticipating capacity
requirements. The suite also includes Unisphere Remote for centrally managing up to
thousands of VNX and VNXe systems.
◆
Operating Environment—Enables managment of resources and services on the array
and consists of VNX OE for File and VNX OE for Block.
◆
EMC Storage Analytics for VNX—Delivers a single, end-to-end view of virtualized
infrastructures (servers to storage) powered by the VMware vCenter Operations
Management Suite analytics engine. EMC Storage Analytics for VNX (ESA) delivers
actionable performance analysis and proactively facilitates increased insight into
storage resource pools to help detect capacity and performance issues so they can be
corrected before they cause a major impact. ESA provides increased visibility, metrics,
and a rich collection of storage analytics for VNX storage infrastructures in VMware
virtual environments.
◆
FAST Suite—Enables deploymentof a FLASH-1st strategy using a small number of flash
drives. This strategy automatically tiers and serves data from the most cost-effective
drive type based on the data need, which lowers storage costs and delivers higher
performance levels for important applications.
◆
Security and Compliance Suite—Helps ensure that data is protected from unwanted
changes, deletions, and malicious activity. You can encrypt data, maintain data
confidentiality, and enforce data retention to meet compliance requirements.
Using EMC VNX Storage with VMware vSphere TechBook
Configuring VMware vSphere on VNX Storage
◆
VNX Local Protection Suite—Includes snapshots for point-in-time recovery and
continuous data protection with EMC RecoverPoint local replication. RecoverPoint has
a new virtual appliance that can reduce costs by 60 percent.
◆
VNX Remote Protection Suite—Includes RecoverPoint Continuous Remote Replication
with DVR-like recovery. RecoverPoint includes a new virtual RecoverPoint appliance to
reduce acquisition cost by 60 percent and provide synchronous replication over IP
and failover to any-point-in-time with VMware SRM.
◆
VNX Application Protection Suite—Makes application-consistent replicas. AppSync
provides a simple, self-service, and SLA-driven approach for protecting virtualized
Microsoft SQL/Exchange and VMware over file and block.
Management tools
Administrators can use the tools discussed in this section to view and manage VNX
storage in a VMware vSphere environment.
EMC Unisphere
EMC Unisphere is the next-generation unified storage management platform that provides
intuitive user interfaces for the newest range of unified platforms including the EMC VNX
family. Unisphere continues to support existing EMC CLARiiON®, EMC Celerra®, and EMC
RecoverPoint SE systems. The Unisphere approach to storage management features
simplicity, flexibility, self-help, and automation—all key requirements for the journey to
the cloud. Unisphere can be customized to the needs of a mid-size company, a
department within large enterprises, or a smaller remote office or branch office
environment. With its plugable architecture, Unisphere is easily extensible and continues
its seamless support for additional EMC offerings, including integration with data
protection and security.
The following Unisphere capabilities greatly simplify mid-tier and entry-level systems
management:
◆
Single sign-on automatically discovers all VNX, CLARiiON, Celerra, and EMC
RecoverPoint SE systems in the environment.
◆
Unisphere Remote provides centralized multibox monitoring for hundreds of VNXe
and VNX systems deployed in remote and branch offices.
◆
The dashboard is a single screen for at-a-glance management, providing
administrators with instant and actionable knowledge about the status of their
virtualized and physical infrastructures.
◆
Unisphere enables administrators to drill down and troubleshoot the most critical
issues from a single view.
◆
Ease of use helps administrators improve IT staff productivity by reducing the amount
of time spent on critical storage administrative tasks.
Management tools
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Configuring VMware vSphere on VNX Storage
Unisphere is an interface based on Java that allows you to quickly provision, manage, and
monitor storage assets. Customizable dashboard views provide realtime details on the
health of the environment, as illustrated in Figure 1.
Figure 1 EMC Unisphere interface
Unisphere includes discovery capabilities for VMware environments. The SP displays
details from vSphere about the virtual storage as it relates to the VNX storage resources.
The Unisphere virtualization management interface is accessible from the Unisphere
Hosts pane. The discovery agent requires vSphere credentials to establish a web services
session with one or more hosts or vCenter servers. Unisphere allows administrators to
understand how VNX storage is being utilized within the vSphere environment.
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Figure 2 illustrates the properties of a sample LUN.
Figure 2 Viewing LUN properties
The interface shows that LUN 17 is assigned to ESX host ucs23.emc.lab and has been
formatted as a VMFS datastore. It also shows that the datastore (named Big Boy) is being
used to support virtual disks on several virtual machines including an Ora11gR2VM.
Unisphere displays the two virtual disks and their capacities and attributes.
You can use information presented in this interface to monitor the environment and
validate virtual disk placement when you configure storage system replication and data
protection policies.
EMC VSI for VMware vSphere
Virtual Storage Integrator (VSI) is a no-charge EMC plug-in for VMware vCenter that is
available to all VMware users who have EMC Symmetrix VMAX family, EMC VNX family, or
VPLEX storage in their environment. VSI enables IT organizations to achieve simplicity and
efficiency in data center operations.
VSI dramatically simplifies management of virtualized storage. It provides management
integration of EMC storage platforms with vCenter, enabling server administrators to easily
handle storage-related tasks. VMware administrators can gain visibility into EMC storage
using the familiar vCenter interface. The familiar interface, along with the ability to
self-provision EMC storage, configure FAST-VP tiering policies, clone virtual machines, and
manage compression from within vCenter, makes managing virtual storage as easy as
ever.
With VSI, IT administrators can do more in less time. VSI offers unmatched access control
that enables you to efficiently manage and delegate storage tasks with confidence. You
can perform daily management tasks with up to 90 percent fewer clicks and up to 10 times
higher productivity. This increase in efficiency also applies to the management of virtual
desktop environments. The EMC VSI plug-in enables you to easily deploy Citrix
XenDesktop and VMware Horizon View virtual desktops from vCenter. To do this, create a
Management tools
25
Configuring VMware vSphere on VNX Storage
fast clone of a master image, and then register the fast clone image with virtual desktop
clients. Using this process, you can deploy multiple XenDesktop or Horizon View virtual
desktops from a single image in minutes.
VSI is a modular framework that allows management features to be added or removed in
support of specific EMC products. This section describes the VSI Unified Storage
Management, Storage Viewer, and Path Management features that are most applicable to
VNX systems.
Figure 3 VSI Feature Manager
VSI: Unified Storage Management
The Unified Storage Management feature of VSI enables vSphere administrators to
manage VNX storage using the vSphere Client.
With the Unified Storage Management feature you can:
◆
Create VMFS datastores and Raw Device Mapping (RDM) devices by provisioning a
new storage device on an ESXi host or data center cluster
◆
Provision datastores in accordance with EMC best practices
◆
Create multiple LUNs and masking for RDMs or Virtual Machine File Systems (VMFS)
◆
Rapidly provision full virtual machine clones or space-efficient fast clones within NFS
datastores
◆
Enable deduplication on selected datastores
◆
Compress virtual NFS disk files
EMC Unified Storage Access Control Utility
Unified Storage Management requires administrative credentials to access and manage
the storage system. The EMC Unified Storage Access Control Utility (ACU) enables the
storage administrator to assign VNX management access to authorized users. It operates
under an explicit deny model with view (read) and management (modify) entitlements
granted at the RAID group, storage pool, or NFS file-system level.
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ACU credentials can be exported as an encrypted key. Storage administrators import the
key into other systems running the vSphere Client. Figure 4 illustrates the steps to create
an access profile.
Figure 4 Unified Storage Access Control workflow
VSI: Storage Viewer
The VSI Storage Viewer feature displays VNX storage device details for LUNs, file systems,
and data paths in the ESXi datastore. You can view VNX device information by selecting an
ESXi storage object in Storage Viewer. This information can help to isolate a particular
storage device when you are troubleshooting the environment. Storage Viewer provides
the following functions and benefits:
◆
Presents storage information in a common view within the vSphere Client
◆
Enables VMware administrators to identify VNX storage properties of VMFS, NFS, and
RDM storage
◆
Presents LUN connectivity and device details for VNX storage
Management tools
27
Configuring VMware vSphere on VNX Storage
Figure 5 provides an example of Storage Viewer for VNX file devices. This view provides
details such as the VNX System ID, file system, RAID type, storage pool, and Data Mover.
Figure 5 Storage Viewer NFS datastore details
Figure 6 provides an example of Storage Viewer for VNX block devices. This view provides
details for the VNX System ID, LUN ID, RAID type, LUN type, and so on.
Figure 6 Storage Viewer VNX block storage details
VSI: Path Management
The VSI Path Management feature includes support for the VMware Native Multipathing
Plug-in and for PowerPath/VE.
The Path Management feature enables you to change the multipath policy and manage
multiple paths from within the VMware vSphere Client. You can change the multipath
policy for several devices based on storage class and virtualization object.
For example, you can manage all Symmetrix devices for a given ESXi host or all CLARiiON
devices for a given VMware vSphere cluster. You can manage multipath policies for
devices owned by both the Native Multipathing Plug-in and PowerPath/VE.
This feature is a valuable asset to administrators who need to maintain consistent
multipath policies across a large virtual datacenter containing a large number or wide
variety of storage devices.
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VMware vStorage APIs for Array Integration
VMware vStorage APIs for Array Integration (VAAI) offloads VMware storage-related
functions from the server to the storage system, enabling more efficient use of server and
network resources for increased performance and consolidation. Letting the VNX series
software perform common data management tasks, such as vMotion migration, results in
greater network IOPS, support for more virtual machines, and faster response time. Other
examples of offloaded tasks include:
◆
Thin Provisioning (block)
◆
Thin Provisioning Stun (block)
◆
Full Clone (file)
◆
Extended Statistics (file)
◆
Space Reservations (file)
◆
Hardware Accelerated Locking (block)
◆
Hardware Accelerated Zero (block)
◆
Hardware Accelerated Copy (block)
VMware vStorage APIs for Storage Awareness
VMware vStorage APIs for Storage Awareness (VASA) is a VMware API that enables the
display of storage information through vCenter. Integration between VASA technology and
VNX makes storage management in a virtualized environment a seamless experience.
Administrators can use the familiar vSphere interface to view details of virtual and
physical resources, provision storage, integrate replication, and offload storage functions
to the storage system. VASA enables the VMware administrator to view basic storage
components including arrays, storage processors, I/O ports, and LUNs.
Installing VMware vSphere on VNX
This section describes the steps required to build the vSphere environment. You can use
the vSphere Auto Deploy and Host Profile features to automate and accelerate multihost
deployments.
The following sections provide configuration guidelines and recommendations:
◆
“Installing the ESXi hypervisor”
◆
“Installing vSphere”
Installing VMware vSphere on VNX
29
Configuring VMware vSphere on VNX Storage
Figure 7 illustrates the workflow for installing and configuring the ESXi systems with a VNX
storage system.
Figure 7 Configuration workflow
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Installing the ESXi hypervisor
Use the instructions on the VMware website to install the ESXi hypervisor. You can install
the ESXi image on the following storage types:
◆
A local server disk
◆
A USB storage device
◆
A storage area network (SAN) SCSI LUN in a boot-from-SAN configuration
Installing vSphere
This section provides instructions for installing vSphere. Installing the image on the SAN
improves performance and reliability through:
◆
RAID-protected storage to reduce the risk of downtime potential of a local disk failure
◆
I/O distribution across multiple spindles and I/O channels
◆
Simplified host replacement in the event of a hardware failure
Note: vSphere 5.x includes Auto Deploy to reduce installation time for larger
environments. The vSphere Installation and Setup Guide provides details on Auto Deploy.
Choose from the following storage protocols, depending on your infrastructure and
environment requirements:
◆
vSphere boot from SAN FC LUNs—ESXi supports booting either through a Fibre
Channel host bus adapter (HBA) or a Fibre Channel over Ethernet (FCoE) converged
network adapter (CNA). Make sure you enable and correctly configure the adapter, so
it can access the boot LUN. See your vendor documentation and the vSphere Storage
document for more information.
◆
vSphere boot from SAN iSCSI LUNs—ESXi version 4.1 and later supports iSCSI
software boot firmware (iBFT). This configuration requires that the network card
supports software initiator boot and at least 1 Gb of throughput. Consult the VMware
Compatibility Guide to verify that the device is supported before beginning this
procedure.
Both protocols provide similar benefits and the configuration tasks are nearly identical.
Configuring a vSphere boot from SAN FC LUNs
1. Cable the hosts. Zone the HBAs to ensure that the host initiators log in to the VNX SPs
when the host is powered on.
2. Gather the following information to configure the environment to use the selected
front-end ports on the array:
• ESXi hostname
• IP addresses
• HBA World Wide Name (WWN)—Obtain the WWN from the Unisphere Host
Connectivity page after the initiators log in to the SPs, or from within ESXi.
• VNX management IP address and credentials
Installing VMware vSphere on VNX
31
Configuring VMware vSphere on VNX Storage
Note: If storage zoning is not complete, obtain the HBA WWN from the SAN switch.
3. Power on the ESXi host.
4. Modify the following host BIOS settings to establish the proper boot order.
• Ensure that the SAN boot device appears immediately after the peripheral devices.
• Unless explicitly required, disable the local RAID SCSI controller on the host to
reduce boot times.
• For software iSCSI, enable iSCSI boot support on the network card.
5. Enable the FC, FCoE, or iSCSI adapter as a boot device, and scan the bus to initiate a
Port Login.
6. Display the properties of the Array Controllers to verify that the adapter can access the
VNX.
7. Access Unisphere to view the Host Connectivity Status. Verify that the adapters are
logged in to the correct SP ports.
8. Boot from SAN requires manual registration of the HBAs. Select the new initiator
records and manually register them using the fully qualified domain name of the host.
Set the failover mode to Asymmetrical Logical Unit Access (ALUA) mode 4 for support
of vStorage API for Array Integration (VAAI).
Note: In some servers, the host initiators may not appear until the host operating
system installation starts (for example, ESXi installations on Cisco UCS, which lacks an
HBA BIOS probe capability).
9. Create a LUN of 20 GB or less on which to install the boot image. Do not store virtual
machines within the datastore created from this LUN.
10. Create a storage group and add the host record and the new LUN to it.
11. Rescan the host adapter to force the host to discover the new device. If the LUN does
not appear, or still appears as LUN Z, recheck the configuration and rescan the HBA.
12. Reserve a specific Host LUN ID to identify the boot devices.
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For example, assign 0 as a Host LUN number to LUNs that contain the boot volume.
This approach makes it easy to differentiate the boot volume from other LUNs
assigned to the host.
Figure 8 Unisphere LUN assignment for ESXi boot device
13. Ensure the CD-ROM/DVD-ROM/USB/virtual media is in the caddy and precedes the
local device in the boot order.
Note: The BIOS does not differentiate a SAN boot device from a local disk.
14. Begin the ESXi installation. Select the DGC device, and follow the installation steps to
configure the host.
Configuring a vSphere boot from SAN iSCSI LUNs
During the system boot, access the iSCSI adapter configuration utility and configure the
HBA as follows. Refer to the vendor documentation for instructions to enable and
configure the following for the iSCSI adapter:
1. Set the IP address and IQN name of the iSCSI initiator.
2. Define the VNX iSCSI target address.
3. Scan the target.
4. Enable the boot settings and the target device.
Installing VMware vSphere on VNX
33
Configuring VMware vSphere on VNX Storage
A sample from a Broadcomm BIOS is provided in Figure 9, illustrating the IQN
Assignment for the VNX iSCSI target.
Figure 9 iBFT interface for VNX target configuration
5. Use Unisphere to configure an iSCSI portal on the VNX platform, as shown in Figure
10.
Figure 10 VNX iSCSI port management interface
VNX iSCSI supports jumbo frames with MTU values of 1488-9000. When configuring
jumbo frames on the VNX, verify that all nodes in the I/O path (host interface, switch
port, and storage interface) support jumbo frames and that their MTU sizes are
consistent.
6. Specify the IP address and IQN name of the iSCSI port from the previous step to
configure the iSCSI target.
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7. Optionally, enable CHAP for to enforce initiator authentication to the iSCSI target.
8. Configure the secondary target with the address information for the iSCSI port on VNX
SP–B.
9. Open Unisphere and complete the following tasks:
• Register the new initiator record.
• Create a new storage group.
• Create a new boot LUN. Add the newly registered host to the storage group.
10. Proceed with the ESXi image installation.
Configuring vSphere with VNX
VNX storage systems are scalable to satisfiy shared storage requirements in mid- to
high-end vSphere environments. The VNX system addresses a broad range of application
and scalability requirements, which makes it an ideal platform for vSphere. The following
topics in this section provide recommendations to consider when you use vSphere with
VNX storage:
◆
“Host connectivity”
◆
“Configuring the Network”
◆
“iSCSI connectivity options for ESXi and VNX”
Host connectivity
Proper host-storage connectivity is a key element to obtaining the most value from the
vSphere and VNX systems. Host connectivity consists of:
◆
Physical cabling techniques
◆
Port zoning or WWN zoning
◆
Host adapter settings
◆
Storage port configuration
Configuring vSphere with VNX
35
Configuring VMware vSphere on VNX Storage
ESXi and VNX provide common support for Fibre Channel, FCoE, iSCSI, and NFS storage
protocols as shown in Figure 11.
Figure 11 VNX storage with VMware vSphere
VNX also offers the CIFS/SMB3.0 file sharing protocol for sharing file systems on Windows
virtual machines.
Note: You can configure ESXi hosts with multiple SCSI transports, such as Fibre Channel
HBAs, and iSCSI software adapters, but accessing the same LUN with multiple SCSI
transport types is not supported. For example, a host can access LUN 0 using FC and LUN 1
using iSCSI, but it cannot access LUN 2 using iSCSI and FC.
This section discusses the following topics:
36
◆
“Physical configuration”
◆
“Port configuration”
◆
“ESX HBAs queue depth”
◆
“Fibre Channel zoning”
◆
“Virtual local area networks”
◆
“Manual initiator registration”
◆
“Fibre Channel over Ethernet”
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Physical configuration
Use the following general best practices when connecting ESXi hosts to the VNX storage
system:
◆
Configure each ESXi host with at least two physical host adapters for device path
redundancy between the host and the storage system.
◆
Cable each physical path through a separate switch for redundancy and fault
tolerance.
◆
Logically, create a separate switch zone for each initiator-target pair, with each
initiator zoned to a separate SP target port.
◆
Add all of the host initiators to a single storage group on the VNX.
Port configuration
VNX storage systems include a minimum of 8 Gb FC ports with expansion slots to
accommodate additional FC, FCOE, iSCSI, and Ethernet I/O connectivity modules. VNX
systems can be customized with connectivity options that scale to match host
requirements and distribute host I/O to the storage system. EMC recommends the
following:
◆
Ensure that ESXi hosts have a minimum of two physical paths to the storage system.
Each path (or pair of paths for path counts greater than two) should be connected to
separate physical switches.
◆
Distribute ESXi host adapter connections across all available SP I/O ports to increase
parallelism to the target device and achieve the best overall response times.
◆
Make note of port requirements for EMC MirrorView™ and EMC RecoverPoint® when
planning port configurations.
Configuring vSphere with VNX
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Configuring VMware vSphere on VNX Storage
Figure 12 illustrates basic FC/FCoE and iSCSI topologies for connecting to the VNX.
Figure 12 ESXi topology with FC/FCoE/iSCSI/NFS connectivity to VNX
Note: The iSCSI hardware initiator configuration is similar to the FC HBA configuration.
ESX HBAs queue depth
The ESX host adapters provide connectivity to the storage system. In most cases, the
default adapter settings are sufficient and no additional configuration is required on the
ESXi or VNX system when the HBA is installed.
One possible exception is the HBA queue depth. The default maximum queue depth value
of an ESXi5 FC HBAs is 64. That means the VMkernel will allow up to 64 outstanding I/Os
at any given time. This value is sufficient for most workloads, particularly when more than
three hosts are accessing a device.
Within the VNX, relevant I/O queues that could impact ESXi host performance are the
front-end host port queue and the LUN queue that is being used to support the datastore.
EMC recommends that you limit the maximum number of I/Os per front-end port to 1,600.
You can add I/O modules to provide additional I/O paths to the storage devices.
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The LUN queue is the most important consideration when tuning host adapter queues. In
most cases, the only time you might consider modifying the maximum HBA queue depth is
when all of the following are true:
◆
The LUN queue depth is larger than the cumulative queue depth of all host adapters
accessing the LUN.
◆
The esx top value of the device queue used percentage (%USD) is continuously at
100.
◆
Queued commands (WQLEN) for the device are greater than 0.
For example, a LUN created from a 20-disk VNX pool in VNX OE for Block version 5.32 and
later has an approximate queue depth of 224. The host adapter queue depth is 64. If the
host is part of a two-node cluster, the cumulative maximum queue depth is 128,which
means the host adapter may be limiting the I/O capabilities of the application.
Note: When altering the maximum queue depth, set Disk.SchedNumRequestsOutstanding
to match this value.
If the multiple ESXi hosts are configured in a datastore cluster, the cumulative queue
depth can quickly surpass the LUN queue. VMware Storage I/O Control (SIOC) helps avoid
a situation where the host queue depths are set too high; however, this example is
provided as an illustration of how to optimize a particular configuration. Unless you are
familiar with the explanation provided, EMC recommends that you leave the queue depth
at the default value of 64.
Fibre Channel zoning
VNX uses single-initiator, single-target zoning. For best results, configure only one active
path between an initiator and the VNX SP. Create two zones per initiator, with one zone
configured for the host initiator and one storage processor A (SP–A) port, and the other
zone configured with the host initiator and one storage processor B (SP–B) port.
In cases where I/O is asynchronous or reliability is favored over performance, an initiator
can be zoned to two ports per SP. This could limit I/O throughput during active periods.
Virtual local area networks
While IP storage systems do not use the term zoning, a similar Ethernet concept is applied
through virtual local area networks (VLANs) on Ethernet switches. VLANs limit the
broadcast domain to switch ports or host adapters that are configured with the same VLAN
ID. VLANs provide a method of network traffic isolation between ESXi IP storage adapters
and the VNX IP storage adapters used to provide iSCSI and NFS connectivity.
Note: EMC recommends that ESXi VMkernel NICs be configured to access the VNX iSCSI
using a separate broadcast domain to isolate network traffic between each ESXi iSCSI
initiator port and VNX iSCSI target port. Separate broadcast domains can be established
using separate nonrouted subnets or VLANs.
Configuring vSphere with VNX
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Configuring VMware vSphere on VNX Storage
Manual initiator registration
In certain cases, such as boot from SAN, you must add host initiators to the VNX to create
storage groups for the boot LUN. For these cases, use the Unisphere host initiator interface
to create the new initiator records. Figure 13 shows how this registration works.
Figure 13 VNX configuration of host initiator
Relevant parameters for the initiator are:
◆
ESXi hostname—User provided
◆
ESXi management IP address—User provided
◆
Initiator type—CLARiiON/VNX
◆
Failover mode—Failover mode 4 (ALUA)
A failover mode defines the scope of SCSI commands that a host can use when connected
to the VNX to support features such as LUN Trespass and multipath behavior. VNX offers
four host failover modes, two of which are applicable for ESXi host initiators:
◆
Asymmetrical LUN Unit Access (ALUA) or Active/active mode (failover mode 4)—When
configured in ALUA mode, the host issues I/O to either VNX SP. The LUN is owned by
one SP that provides an optimal I/O path. The peer SP provides a non optimal path
that is used only when all optimal paths have failed or are otherwise unavailable.
Failover mode 4 is required for support of VAAI operations on VNX. EMC recommends
using mode 4 for all ESXi initiators connected to VNX.
◆
Active/passive mode (failover mode 1)—This mode uses a single optimal or preferred
path to the SP that was assigned to the LUN when it was created. The LUN remains
active on that SP unless a disruption occurs at the SP or host level. This mode was
used in earlier EMC CX® platforms.
ESXi version 4.0 and later are compliant with ALUA. When configured with failover mode 4,
the ESXi host sends I/O to the VNX LUN using the active/optimized path. If an
active/optimized path becomes unavailable, the host attempts to use another
active/optimized path on the SP that owns the LUN. If all active/optimized paths are
unavailable and the host has active paths to the non optimized SP, it issues a trespass
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request to the LUN via the peer SP. The peer SP becomes the LUN owner and satisfies all
subsequent I/O requests. The Native Multipathing Plug-in “Storage multipathing” on
page 59 provides more details on path trespass and restore.
For vSphere version 5.1 and later, all LUNs are trespassed back to the default owner when
the paths are restored.
Fibre Channel over Ethernet
Native Fibre Channel over Ethernet (FCoE) support, included with the VNX platform, offers
a consolidated cabling option between servers, switches, and storage subsystems. FCoE
connectivity allows general server network traffic and storage I/O to be transmitted to and
from the server through fewer high-bandwidth, IP-based physical connections.
Converged network adapters (CNAs) and FCoE software initiator support in vSphere 5
reduce the physical hardware footprint requirements to support the data traffic and
provide a high flow rate through the consolidated network.
High-performance block I/O, previously handled through a separate FC-based data traffic
network, can be merged into a single IP-based network with CNAs or 10 GbE adapters that
provide efficient FCoE support.
VNX expansion modules add 10 GbE FCoE connectivity with minimal configuration.
Configuring the Network
Equipment
Consider the following recommendations when configuring Ethernet storage networks:
◆
Use CAT 6 cables to connect to copper Ethernet networks.
◆
Use network switches that support a multichassis link aggregation technology, such
as cross-stack EtherChannel or virtual port channeling. “Multipathing considerations
for NFS” on page 66 provides more details.
◆
Consider FCoE hardware adapters with 10 GbE converged network switches for
consolidated storage networks. “Fibre Channel over Ethernet” on page 41 provides
more details.
◆
Select a switch vendor that includes 10 GbE support for NFS, iSCSI, or FCoE.
Configuring Ethernet networks
Consider the following when configuring IP storage networks:
◆
Use a dedicated physical switch or isolated VLAN to provide the most efficient
network.
◆
On network switches that are also used for the storage network:
• Enable flow control.
• Enable spanning tree protocol with either RSTP or port-fast enabled.
• Restrict bridge protocol data units (PDUs) on storage network ports.
◆
In general, ESXi host I/O is small and random; in most cases, jumbo frames (Ethernet
MTU greater than 1,500) provide minimal benefit.
Configuring vSphere with VNX
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Configuring VMware vSphere on VNX Storage
Large block I/O and sequential workloads can benefit from larger frame sizes. If
configuring jumbo frames, ensure that each network interface (host, switch, VNX) in
the I/O path uses the same MTU value.
◆
vSphere 5 supports an FCoE software initiator on supported network adapters.
Consider an FCoE software initiator with 10 GbE network switches to consolidate
storage and switching equipment.
Configuring the VMkernel port in ESXi
ESXi uses VMkernel ports for systems management and IP storage interfaces. IP storage
interfaces are used to access one or more VNX iSCSI network portals or NFS servers.
Figure 14 VMkernel port configuration
To configure a VMkernel interface for NFS, use Figure 14 as a guide and complete the
following steps:
1. Create a new virtual switch to support the IP storage interfaces.
2. Assign a network label that describes what the interface is used for, such as NFS-DM1,
iSCSI1, iSCSI-OraDB, and so on.
3. For NFS, assign a network adapter.
For best performance use a nonrouted interface on the same broadcast domain as the
VNX NFS server.
4. In the VMkernel - IP Connection Settings dialog box, specify the following VMkernel IP
settings:
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• IP address
• Subnet mask
• Default network gateway
Notes:
• Do not use DHCP.
• ESXi management and VMkernel interfaces share the same routing table of the
ESXi host. As a result, the management interface routes storage I/O when the NFS
server is configured to use the same subnet. To prevent this from happening, use
separate subnets or VLANs for the management and storage networks.
5. Click Next.
The Ready to Complete dialog box appears.
6. Verify the settings, and then click Finish to complete the process.
iSCSI connectivity options for ESXi and VNX
VNX iSCSI architecture provides a flexible IP storage system that can be customized for
almost any network topology. Each iSCSI network port supports multiple virtual interfaces,
and each virtual interface can reside on a different address and/or VLAN. Furthermore,
each iSCSI interface presents a unique iSCSI target, allowing initiators to be configured to
connect to one or more targets in support of high availability and multipath technology.
◆
“VNX iSCSI target”
◆
“ESXi iSCSI initiator”
◆
“VMkernel port group assignment”
◆
“Subnet configuration”
VNX iSCSI target
Figure 15 illustrates a basic iSCSI network design for a VNX that has a single SLIC with four
Ethernet ports. Each port can support multiple virtual interfaces and be addressed across
subnets and VLANs. In this illustration, a one-to-one relationship exists between the
physical port and the subnet, and each port is configured with a separate subnet address.
Figure 15 VNX multiple subnet iSCSI target port addressing
Configuring vSphere with VNX
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Configuring VMware vSphere on VNX Storage
ESXi iSCSI initiator
ESXi offers two iSCSI connectivity options:
◆
Hardware initiator—This configuration uses a dedicated storage adapter card and
Ethernet network to access the iSCSI target. Most adapters provide BIOS-level utilities
to configure the initiator settings, including the VNX target addresses. Thereafter, the
adapter appears and operates as a host storage adapter similar to those within the
vSphere environment.
◆
Software initiator—This option is implemented as a VMkernel software driver that is
dependent on one or more ESXi 1 GbE or 10 GbE network interfaces to transport the
iSCSI traffic. Configuration of the software initiator is provided through vCenter or ESXi
command line utilities.
This document covers the generic configuration of iSCSI with VNX. It focuses heavily on
the software initiator, because proper configuration depends on understanding some
topology nuances.
ESXi software initiator
The ESXi software initiator is implemented as a VMkernel device driver. It relies on one or
more VMkernel ports (vmknics) on the ESXi host to support the iSCSI sessions and
transport data to the VNX. Each VMkernel port depends on one or more physical network
interfaces (vmnics).
◆
The software initiator should be configured with two or more physical paths (vmnics)
to the storage system for redundancy and scaling.
◆
For performance reasons, iSCSI interfaces should not be shared with other ESXI host
services.
◆
Use dedicated physical interfaces for iSCSI and provide additional interfaces for
vSphere services such as NFS, vMotion, and Virtual Machine networks.
VMkernel port groups can be configured with a single physical adapter or grouped
together into “NIC teams” for increased availability.
◆
NIC teaming provides increased reliability at the iSCSI session or path level; however,
it does present the potential to reserve network resources that could be used to
process I/O.
◆
Performance-centric environments using VNX might be better served by configuring
separate port groups for each physical adapter and using the multipath and failover
capabilities of VNX and the Native Multipathing Plug-in to mitigate a single vmnic
failure.
VMkernel port group assignment
VMkernel port groups are associated with the software initiator in one of two ways:
explicitly through port binding or implicitly by configuring the initiator with a discovery
address.
Explicit assignment (port binding)
This configuration method is required for iSCSI storage systems that use a single iSCSI
target. This option provides multipathing by binding multiple VMkernel port groups to the
software initiator.
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The following characteristics apply to port binding:
◆
The VMkernel port group is dedicated to the iSCSI initiator.
◆
All VMkernel port groups must use the same subnet address.
Note: VNX is a multitarget architecture. While technically possible, port binding is not
supported on VNX.
Implicit assignment (recommended for VNX)
This option is used when the iSCSI storage system supports multiple targets or network
portals. With this configuration, no VMkernel port groups are bound to the software
initiator. The VMkernel determines which VMkernel port groups to use based on the port
group's ability to access and establish an iSCSI session with the VNX iSCSI targets.
The following characteristics apply to configurations that do not use port binding:
◆
The VMkernel port group is shared with other VMkernel services.
◆
NFS servers configured on the same network may impact iSCSI service.
◆
Single subnet configurations will not distribute I/O across all adapters.
During the ESXi initiator-iSCSI target nexus, the initiator uses the dynamic discovery
address to access the target and issue a SCSI “send targets” inquiry command. The iSCSI
target responds with a list of all configured iSCSI targets and network (portal) addresses. 1
The VMkernel performs a network connectivity test between each VMkernel port group
and VNX network portal address returned from the SCSI send targets command. Validated
network paths are used to establish iSCSI sessions with the VNX. Paths that result in
network or login failure are not retried.
1. The addresses are visible in the static address tab of the vCenter software initiator properties
window.
Configuring vSphere with VNX
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Configuring VMware vSphere on VNX Storage
Figure 16 illustrates the steps required to configure the iSCSI initiator using implicit
assignment.
Figure 16 iSCSI Software initiator configuration in vSphere 5
The VNX network configuration is extremely flexible. The VNX iSCSI targets can be
presented with a single network or multiple networks as illustrated in Figure 17. Basic
configurations use a single subnet which simplifies the configuration of the software
initiator.
Subnet configuration
Single subnet configuration
In this example, the VNX system has two iSCSI targets configured (one on SPA and one on
SPB). This results in one optimal and one non-optimal path to each storage pool LUN.
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Multiple Subnet Configuration
In this example the VNX system has four iSCSI targets configured (two on SP–A and two on
SP–B). Two networks are used for the host and storage addresses as illustrated in Table 2.
Assuming the networks are non-routable, the configuration results in four iSCSI sessions
with two optimal and two non-optimal paths to each storage pool LUN.
Note: If the VMkernel network ports can route I/O to all four VNX target ports, each LUN
will have 32 potential I/O paths resulting in 8 active/optimal paths and 8 non-optimal
paths. However, the additional sessions to the targets do not provide a performance
improvement.
Table 2
Multiple Subnet Configuration IPs/IQNs
Network
Target IQN
192.168.10.x
iqn.1992-04.com.emc:cx.fnm00103900200.a4
iqn.1992-04.com.emc:cx.fnm00103900200.b4
192.168.11.x
iqn.1992-04.com.emc:cx.fnm00103900200.a5
iqn.1992-04.com.emc:cx.fnm00103900200.b5
Figure 17 Topology diagram for multiple-subnet iSCSI configuration
Single network address space
All of the ports are on the same subnet: 192.168.10.0/24. Based on the Flare 30 changes,
this configuration should be supported from a technical standpoint so that you can
configure multiple VMkernel adapters and all VNX iSCSI FE ports using the same subnet.
Advantages and disadvantages of using a single network address space are:
◆
Pros: Simple to configure, scalable
◆
Cons: Each initiator establishes a session with all VNX target ports.
• Results in eight iSCSI sessions in this example
• Results in 16 sessions when 4 VMkernel and target ports are used
• Requires NIC teaming or VLANs to take advantage of all paths
Configuring vSphere with VNX
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Configuring VMware vSphere on VNX Storage
Multiple subnet configuration (VNX Config)
The second option is to create multiple subnets or broadcast domains. This is done by
defining separate network addresses for each VMkernel NIC and VNX SP port pair.
Figure 17 illustrates a configuration that uses two subnets (subnet 192.168.10 and
192.168.11). To simplify this example, the endpoint or host component of the network
address is the same for all interfaces.
Advantages and disadvantages of using multiple subnets are:
◆
Pros: 1:1 source to target/LUN session subscription
Performs I/O distribution across all paths when the host and target LIN are configured
with native multipathing or PowerPath.
◆
Cons: Requires additional network setup
The host can still establish eight iSCSI sessions if subnets are routable.
Configure separate broadcast domains for each iSCSI initiator and VNX target pair (that is,
SP–A4 and SP–B4). A broadcast domain can be created in either of the following ways:
◆
Configure a network subnet and place all of the nodes in that subnet.
◆
Configure a VLAN that is port-based or one that uses packet tagging. With port-based
VLANs all switch ports are assigned to a particular VLAN ID. Network traffic is
restricted to ports that are assigned to that VLAN. Packet tagging uses a field in the
Ethernet frame to carry the VLAN ID. Only systems that have tagging configured for
that VLAN ID will see those packets.
If the ESXi host uses PowerPath/VE, or native multipathing round-robin, then the host has
two active/optimized paths to each LUN and two standby paths that will be used in the
event that both active/optimized paths become unavailable.
In both cases, if the LUN is owned by SP–A, the SP–B paths are not used unless a failure of
both SP–A paths occurs.
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For additional connectivity, configure additional VMkernel port groups and use network
addresses to distribute them across addition VNX iSCSI network portals. The sample
configuration illustrated in Figure 18 provides additional dedicated I/O paths for four VNX
iSCSI target ports. In this configuration, two dedicated paths are available to each SP. This
provides increased bandwidth to any LUNs presented to the host.
Figure 18 Recommended configuration for VNX iSCSI targets
Delayed acknowledgement settings for iSCSI
In some circumstances the VNX and ESXi hosts have encountered suboptimal iSCSI
performance when using 10 GbE interfaces with the delayed acknowledgment (Nagle's
algorithm) enabled.
Delayed acknowledgement is a TCP optimization intended to reduce network packets by
combining multiple TCP acknowledgements into a single response. This optimization
works well when many TCP packets are being transmitted between the ESXi host and the
VNX. However, in some cases, such as when a single virtual machine or ESXi host
performs sequential writes, the VNX does not have any data to return. In this case, the
host waits for an acknowledgement to its write, and, due to Nagle, the VNX groups
multiple acknowledgments and waits for the timeout (200 ms) to elapse before sending
them all in a single response. This behavior has the potential to insert 200 ms delays into
the I/O stream.
Disable the iSCSI Delayed Acknowledgement setting on the 10 GbE NIC in cases where
performance delays are observed.
Configuring vSphere with VNX
49
Configuring VMware vSphere on VNX Storage
Figure 19 illustrates how to disable this setting.
Figure 19 Disable Delayed Acknowledgement setting on storage adapter
VMware provides the following steps in Knowledge Base article 1002598 to disable
delayed acknowledgement in ESX/ESXi hosts that might experience read/write
performance issues with certain storage arrays:
1. Log in to the vSphere Client and select the host.
2. Select the Configuration tab.
3. Select Storage Adapters.
4. Select the iSCSI vm HBA to be modified.
5. Click Properties.
6. Do one of the following:
• Modify the Delayed ACK setting on the discovery address (recommended):
a. On a discovery address, select the Dynamic Discovery tab.
b. Select the Server Address tab.
c. Click Settings.
d. Click Advanced.
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• Modify the Delayed ACK setting on a specific target:
a. Select the Static Discovery tab.
b. Select the target.
c. Click Settings.
d. Click Advanced.
• Modify the Delayed ACK setting for all targets:
a. Select the General tab.
b. Click Advanced.
7. Reboot the host.
Provisioning VNX storage for vSphere
VNX storage is presented to ESXi hosts in two forms: NFS exported file systems and SCSI
LUNs. While NFS file systems are used only as vSphere datastores, LUNs can be formatted
for datastore use or assigned to a virtual machine as a RDM virtual disk.
RDM disks are assigned directly to a virtual machine without VMFS formatting. The
VMkernel generates a VMDK mapping file for the RDM with LUN information including the
unique device ID. The virtual machine issues I/Os directly to the VNX LUN using the UUID.
RDMs reduce file system overhead and device contention that can be introduced when
multiple virtual machines share a VMFS volume.
Creating an NFS datastore using VSI
EMC provides vCenter integration tools to automate and simplify the creation of storage
devices and datastores using the VSI Unified Storage Management feature.
The high-level steps to configure VNX NFS file systems for vSphere are:
1. Create a VNX file system.
2. Export the file system to the ESXi host through VSI Unified Storage Management or
Unisphere.
3. Add the file system as an NFS datastore in ESXi.
You can use Unisphere to complete these steps manually or you can use the Unified
Storage Management feature, as follows:
1. From the vSphere Client right-click a host or cluster object.
Note: If you choose a cluster, folder, or data center, all ESXi hosts within the object are
attached to the newly provisioned storage.
2. Select EMC > Unified Storage.
3. Select Provision Storage.
The Provision Storage wizard appears.
4. Select Network File System, and then click Next.
Provisioning VNX storage for vSphere
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Configuring VMware vSphere on VNX Storage
5. In the Storage System table, select a VNX.
If a VNX does not appear in the Storage System table, click Add. and provide the
information for the new VNX in the Add Credentials wizard.
6. In the Datastore Name field, type the datastore name, and then click Next.
The Data Mover Details dialog box appears, as shown in Figure 20.
Figure 20 File storage provisioning with Unified Storage Management
7. From the Data Mover Name list box, select a Data Mover.
8. From the Data Mover Interfaces list box, select a Data Mover interface, and then click
Next.
9. Select Create New NFS Export, and then click Next
10. From the Storage Pool list box, select a storage pool.
Note: All available storage within the storage pool is displayed. Ensure that the
storage pool you select is designated by the storage administrator for use by VMware
vSphere.
11. In the Initial Capacity field, type an initial capacity for the NFS export and select the
unit of measurement from the list box at the right.
12. If thin provisioning is required, select Thin Enabled to indicate the new file systems
are thinly provisioned.
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Note: When a new NFS datastore is created with EMC VSI, Thin Provisioning and
Automatic File system extension are automatically enabled. In the New NFS Export
window, type the values for the initial capacity and maximum capacity of the
datastore.
Figure 21 Creating a new NFS datastore with Unified Storage Management
13. Select the unit of measurement from the list box to the right.
If Virtual Provisioning is enabled for the file system, the maximum capacity is required.
Figure 21 shows an initial capacity entered in the Max Capacity field for the NFS
export.
14. Click Advanced.
The Advanced Options dialog box appears.
The following settings are important for optimal VNX with VMware vSphere
performance:
• High Water Mark—Specifies the percentage of consumed file system space at
which VNX initiates automatic file system extension. Acceptable values are 50 to
99. (The default is 90 percent.)
• Direct Writes—Enhances write performance to the VNX file system. This mechanism
enables well-formed NFS writes to bypass the Data Mover cache. The Direct Writes
mechanism is designed to improve the performance of applications with many
connections to a large file, such as virtual disk files. When replication is used,
Direct Writes are enabled on the secondary file system as well.
Provisioning VNX storage for vSphere
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Configuring VMware vSphere on VNX Storage
15. Review the settings, click OK, and then click Finish.
Provisioning block storage for VMFS datastores and RDM volumes
To add a VMFS datastore to a vSphere environment, you must create a LUN, unmask the
LUN, rescan the host, and create a VMFS datastore.
The Unified Storage Management feature of VSI provides the following benefits:
◆
Offers an integrated workflow to automate LUN creation, LUN unmasking, host rescan,
and VMFS datastore creation.
◆
Allows the administrator to create one or more VMFS volumes and ensures that each
volume is correctly aligned on 64 KB boundaries.
◆
Performs LUN creation and assignment without formatting so that the LUN can be
surfaced as an RDM disk to a virtual machine.
Use the Unified Storage Management feature to provision storage as follows:
1. Right-click a vSphere object, such as a host, cluster, folder, or data center in vCenter.
Note: If you choose a cluster, folder, or data center, all ESXi hosts within the object are
granted access to the newly provisioned storage.
2. Select EMC > Unified Storage.
3. Select Provision Storage.
The Provision Storage wizard appears, as shown in Figure 22.
4. Select Disk/LUN, and then click Next.
Figure 22 File storage provisioning with Unified Storage Management
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5. In the Storage System table, select a VNX. If a VNX does not appear in the Storage
Array table, click Add and add the VNX storage system using the Add Credentials
wizard.
6. Select the storage pool or RAID group on which you want to provision the new LUN,
and then click Next.
7. Select the datastore volume format as VMFS-3 or VMFS-5, and then click Next.
8. Select VMFS Datastore or RDM Volume.
9. Select an SP to own the new LUN and select Auto Assignment Enabled. Click Next.
Notes:
• Install and correctly configure failover software for failover of block storage.
• Unlike VMFS datastores, RDM LUNs are bound to a single virtual machine and
cannot be shared across multiple virtual machines unless clustering is established
at the virtual machine level. Use VMFS datastores unless a one-to-one mapping
between physical and virtual storage is required.
10. For VMFS datastores, complete the following steps:
a. In the Datastore Name field, type a name for the datastore.
b. From the Maximum File Size list box, select a maximum file size.
11. From the LUN ID list box, select a LUN number.
12. From the Default Owner list box, select the SP that will own the new LUN.
13. In the Capacity field, type an initial capacity for the LUN and select the unit of
measurement from the list box.
Figure 23 illustrates this action.
Figure 23 Creating a new VMFS datastore with Unified Storage Management
Provisioning VNX storage for vSphere
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Configuring VMware vSphere on VNX Storage
14. Click Advanced to configure the VNX FAST VP policy settings for the LUN.
The tiering policy options are:
• Auto-Tier—Distributes the initial data placement across all drive types in the pool
to maximize tier usage for the LUN. Subsequent data relocation is based on LUN
performance statistics to ensure data is relocated among available tiers according
to I/O activity.
• Highest Available Tier—Sets the preferred tier for initial data placement and
subsequent data relocation (if applicable) to the highest performing disk drives
with available space.
• Lowest Available Tier—Sets the preferred tier for initial data placement and
subsequent data relocation (if applicable) to the most cost-effective disk drives
with available space.
15. Click Finish.
When these steps are completed, Unified Storage Management initiates the following
tasks:
• Creates a LUN in the selected storage pool
• Assigns the LUN to the designated SP
• Adds the LUN to the storage group associated with the selected ESXi hosts, making
it visible to the hosts
• Creates the VMFS datastore on the newly created LUN if VMFS is chosen
16. Select Configuration > Storage to see the newly provisioned storage.
Unified storage considerations
A good storage configuration starts with a plan. A proper plan makes configuration easier,
and documented configuration plans provide a useful reference for validation and
support.
The recommendations in this section provide general guidance. Specific configuration
suggestions are driven by the actual workload.
Begin storage planning with an assessment of the application requirements. The primary
factors that determine the storage configuration are:
◆
Required throughput measured in IOPS or bandwidth in MB/s
◆
Response time or latency measured in milliseconds
◆
Storage capacity
Understand the application profile and response time requirements, and translate them
into storage resource requirements.
The following sections include general considerations and recommendations that apply to
VNX storage arrays:
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◆
“Datastore virtual machine density”
◆
“Best practices for extending a datastore”
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◆
“Solid state volumes for VNX OE for File”
◆
“General recommendations for storage sizing and configuration”
◆
“Storage multipathing”
Datastore virtual machine density
When sizing the number of virtual machines per datastore, the following points are useful:
◆
vSphere support for VAAI and Storage I/O Control (SIOC) alleviates many of the
historical factors that limited virtual machine scalability in a datastore. vSphere 5 also
includes features such as Storage Distributed Resource Scheduler (SDRS) to balance
virtual machine workloads across storage resources.
◆
VNX includes VAAI support, multiple classes of storage devices, and support for an
increased number of storage devices, ports, and LUNs.
◆
The correct number of virtual machines to add to the datastore is determined by I/O
workload, response time, and capacity.
◆
Depending on the configuration, VNX LUNs are capable of delivering hundreds of
thousands of IOPS. EMC has produced results for VDI that illustrate support for
hundreds of virtual machines with a datastore with medium workloads (5 IOPS per
virtual machine).
◆
For performance-sensitive environments where ESXi host clusters generate significant
IOPS, create multiple LUNs to distribute the I/O across multiple LUN queues.
◆
For non-SIOC environments, the VMkernel serializes and queues I/O from all virtual
machines that use the LUN. The potential exists for a long LUN queue that can result in
longer response times.
◆
SIOC alleviates this condition by throttling the LUN queue depth when response times
exceed the defined congestion parameter. Enable and configure SIOC based on the
recommendations provided in “Storage I/O Control” on page 87.
◆
If SIOC is not enabled, this control falls to a number of other ESXi host parameters
including Disk.SchedNumReqOutstanding, which, by default, limits to 32 the number
of requests the host sends to a LUN. The value limit ensures that no single virtual
machine monopolizes the LUN queue.
Best practices for extending a datastore
VMFS supports the use of multi-LUN or multi extent volumes. Adding a new extent
increases the capacity for a VMFS datastore that grows short on free space.
Using multi-LUN volumes adds unnecessary complexity and management overhead. If the
VNX has enough free space, use the following best practices for multi-LUN extents:
◆
Extend the LUN and grow the VMFS volume within vSphere.
◆
Create a new device and use LUN migration to migrate data to it. This also provides
the ability to change the underlying storage type since LUN migration to any LUN of the
same or larger capacity is possible.
◆
Use SDRS to create a datastore cluster and allow it to manage virtual machine
placement.
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Configuring VMware vSphere on VNX Storage
Solid state volumes for VNX OE for File
Follow these general configuration recommendations for flash drives with VNX OE for File:
◆
Use Automatic Volume Management (AVM) pools for general NFS datastores.
AVM templates for enterprise flash drives (EFDs) are RAID 5 (4+1 or 8+1) and RAID 1/0
(1+1)
◆
Create four LUNs per EFD storage pool and distribute LUN ownership among SPs.
Note: This recommendation does not apply to other storage pools.
◆
Use Manual Volume Management (MVM) for custom volume configurations not
available with AVM.
◆
Volumes can be striped across EFD LUNs from the same RAID Group.
General recommendations for storage sizing and configuration
VNX enables administrators with an understanding of the I/O workload to provide
different service levels to virtual machines. This is done primarily through the storage
class and advanced LUN capabilities.
If workload details are not available, follow these general guidelines:
58
◆
Allow for overhead in the datastore for snapshots, swap files, and virtual machine
clones. Try to limit datastores to 80 percent of their capacity. This enables
administrators to quickly allocate space, create VMware snapshots, clone virtual
machines, and accommodate virtual machine swap files.
◆
The VM boot virtual disk can reside on either an NFS or VMFS datastore. A virtual
machine boot disk generates a limited number of IOPS. For example, during boot a
standard Windows XP desktop generates about 350 IOPS for a period of about 30
seconds.
◆
Do not create more than three virtual machine snapshots, and do not keep them for
an extended period of time. Instead, use a virtual machine clone to get a point-in-time
image of a virtual machine to avoid the logging activity within the datastore that
results from change tracking. VNX Snapshots offload the overhead on the ESXi host
and provide a suitable alternative to vSphere snapshots.
◆
Enable SIOC to control periods of high I/O traffic, and monitor SIOC response times
within vSphere. If response times are consistently high, rebalance the virtual
machines with VMware vSphere Storage vMotion, or configure an SDRS cluster to
automate redistribution.
◆
Use FAST Cache with the appropriate workload. FAST Cache is beneficial for random
I/O workloads that are frequently accessed. Sequential workloads typically read or
write data once during the operation. Sequential data access patterns often require a
longer period of time to warm the FAST Cache and are better handled by SP read
cache.
◆
Monitor the amount of data relocated on FAST VP LUNs. If the FAST VP pools
consistently rebalance a large percentage of data, consider increasing the number of
disks in the highest tier.
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The following recommendations are specific to workload size:
◆
Low workload
• Virtual desktop environments have relatively low I/O requirements with occasional
bursts caused by operations such as booting, virus scanning, and logging on in
large numbers.
• Use LUNs enabled with FAST Cache, or Host Cache, to reduce the impact of I/O
bursts within the virtual machines.
• Use Host Cache on SSD for linked clone VDI environments. Consider the use of
Host Cache on EFDs to support virtual swap files.
• Use RAID 5 FAST VP pools with a combination of SAS and NL-SAS drives for file
servers with static files.
Medium-size SAS drives, such as the 300 GB, 10k RPM drive, may be appropriate
for these virtual machines.
• Use 1 and 2 TB NL-SAS drives for datastores that are used to store archived data.
• Use RAID 6 with NL-SAS drives greater than 1 TB.
Infrastructure servers, such as DNS servers, are primarily processor-based with
relatively little I/O. Those virtual machines can be stored on NFS or a FAST VP pool
consisting of SAS and NL-SAS drives.
◆
Medium workload
• Medium DB application workloads are good candidates for SAS datastores.
• FAST Cache or FAST VP configured with as few as two SSDs provides a good option
for heavily used tables within the database.
• Use a separate RAID 10 datastore for DB log virtual disks.
◆
High workload
• Applications with hot regions of data benefit from the addition of FAST Cache.
• Store DB log files on separate virtual disks in RAID 10 VMFS, NFS, or RDM devices.
• Allocate RAID 10 protected volumes, EFDs, or FAST Cache to enhance the
performance of virtual machines that generate high small-block, random I/O read
workload. Consider dedicated RDM devices for these virtual machines.
• Use RAID 1/0 LUNs or file systems for virtual machines that are expected to have a
write-intensive workload.
Storage multipathing
Multipathing establishes two or more I/O paths between a host and a LUN to address two
important areas:
◆
Reliability—Multiple I/O paths ensure that access to application data is maintained in
the event of a component failure.
◆
Scalability—Hosts can parallelize I/Os across multiple storage adapters to increase
efficiency and balance storage resource utilization.
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Configuring VMware vSphere on VNX Storage
VNX storage systems have two SPs or storage targets. Access to a LUN is provided through
all front-end host ports on the SPs. VNX provides several target access methods that
determine how the LUN IO is processed. Pool LUNs configured for vSphere default to
asymmetric active/active or ALUA mode as illustrated in Figure 24.
VNX storage systems define a set of target port groups for each new LUN. One port group is
assigned for the SP that owns the LUN and one for the nonowner. The assigned owner is
also the default owner for that LUN, which means any time an event occurs relating to
ownership, the VNX will attempt to place the LUN back on that SP. The port group of the
owning SP provides the optimal path to the LUN through all of its front-end I/O ports. The
peer SP provides a non-optimal path that can also satisfy I/O; however, the I/O must
traverse an internal bus to satisfy the request.
Figure 24 illustrates the concept of LUN ownership and I/O paths. When a LUN is owned by
SP–A, optimal paths to the LUN are through the I/O ports of SP–A.
Figure 24 LUN ownership
LUN trespass
VNX transfers LUN ownership to the peer SP when certain host or storage system states
are encountered. Examples include instances when:
◆
A host loses access to the SP due to an environmental or hardware failure.
◆
The VNX storage processor is undergoing a software update.
◆
A significant number of I/Os are being received down the non-optimized path.
Under these conditions LUN ownership is transferred to the peer SP and hosts must use
the paths to that SP to perform I/O to the LUN. A LUN is considered to be trespassed when
its current owner is different from its default owner.
LUN failover modes are introduced in “Manual initiator registration” on page 40. VNX
provides multiple failover modes including active/standby (mode 1) and active/active
(ALUA), which is the recommended failover mode for vSphere 4 and later versions.
ESXi hosts are ALUA-aware. When accessing a VNX LUN in ALUA mode, the VMkernel can
issue ALUA commands to determine the state of the LUN path, including the optimal path.
The default LUN configuration for ESXi issues I/O only to the optimal paths unless they all
become unavailable and only non-optimal paths remain. If all active optimized paths
become unavailable the host issues an explicit trespass to the peer SP and resumes I/O
using that SP.
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During a host boot the Native Multipathing Plug-in module uses ALUA commands to
identify the default owner and optimal paths to its LUNs. If a LUN has been trespassed by
the host and the path to the default owner is available, the host issues a command to VNX
to restore it to the default owner.
These processes are illustrated in Figure 25.
Figure 25 LUN trespass
VNX active/active LUN assignment
The VNX provides the capability to assign a classic LUN to both SPs and thus service I/O to
the LUN through both SPs. With true active/active, a LUN can be simultaneously read from
and written to using both storage processors.
Active/active applies to classic LUNs, which are LUNs created from RAID group storage.
LUNs created from storage pools continue to provide ALUA mode, which is described in
“VNX availability” on page 21.
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Configuring VMware vSphere on VNX Storage
Active/active is possible because MCx introduced a locking technology for LUN read and
write access. SPs communicate with each other using the Communication Manager
Interface (CMI). The new VNX hardware has a PCI Gen3 bus connecting both SPs, over
which CMI runs between SPs, as illustrated in Figure 26.
Figure 26 Stripe locking service
An SP must request an exclusive lock for a logical block addressing (LBA) range on a LUN
prior to proceeding with the write from a locking service. A locking service communication
between SPs is done over the CMI bus. The SP proceeds with the write on a successful lock
grant.
Similarly, a shared-read lock must be taken out for reads. The SP needs to know whether
to read from the disk or from a peer SP's cache, if it has newer data than the disk (dirty
cache pages have not been flushed from the peer SP to the disk yet). Once the I/O is
complete, the lock is released.
Active/active LUNs provide the potential for significant performance improvements in
most application environments.
vSphere native multipath
The ESXi VMkernel provides a pluggable storage architecture (PSA) to support different
multipath modules. Figure 27 illustrates the PSA used with vSphere.
Figure 27 VMkernel pluggable storage architecture
The default module is Native Multipathing Plug-in, which presents several path
configuration options to determine:
62
◆
The path selection plug-in (PSP) (used when multiple physical paths exist)
◆
Path failure and recovery policy
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Configuring VMware vSphere on VNX Storage
The Native Multipathing Plug-in provides the framework to discover new LUNs and identify
the storage array type plug-in (SATP), the initiator mode, and LUN properties such as the
default SP that owns the LUN.
The Native Multipathing Plug-in uses the SATP to assign a PSP to the LUN. Run the
esxcli storage nmp satp list command to view the rules.
Native Multipathing Plug-in PSPs
vSphere has four native PSPs:
◆
Fixed Path Array Preference (AP)—Queries the array for the preferred path and uses
that path unless a failure occurs. This PSP has been removed in vSphere 5.0 and later
versions. It is the default vSphere 4.1 PSP for VMW_SATP_ALUA_CX.
◆
Fixed Path—Uses the single preferred (active/optimized) I/O path for the VNX LUN. If
the preferred path is unavailable, it uses an alternate path. It reverts to the preferred
path when it is restored. It is the default vSphere 5.0 PSP for VMW_SATP_ALUA_CX.
◆
Round Robin—Uses all active/optimized paths between the host and the LUN. The
host sends a fixed number of I/Os down the first active/optimized path, followed by a
fixed number of I/Os down each subsequent active/optimized path. Non-optimized
paths are not used for I/O, unless all active/optimized paths have failed. This is the
default vSphere 5.1 PSP for VMW_SATP_ALUA_CX.
◆
Most Recently Used (MRU)—This option is used by all vSphere hosts when the failover
mode of the host initiator records is set to one. It uses the first LUN path detected
when the host boots. The host continues to use that path as long as it remains
available. If a path failure occurs, the host attempts to use another path on the same
SP or issues a trespass to the peer SP. This is the default vSphere 5.0 and 5.1 PSP for
VMW_SATP_CX.
Each SATP uses a predefined PSP agreed upon by VMware and the storage vendor.
Figure 28 illustrates the esxcli command output to identify the PSPs used for VNX systems
in vSphere 5.1.
Figure 28 Esxcli command output
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Configuring VMware vSphere on VNX Storage
ESX 5.1 contains an enhancement to the Round-Robin Native Multipathing Plug-in PSP
that allows auto restore to the preferred (default) VNX SP when a fabric failure (failed
HBA/NIC/CNA, switch, or SP front-end port) to that preferred SP is repaired. Table 3 shows
the recommended Native Multipathing Plug-in PSP.
Table 3 Recommended Native Multipathing Plug-in path selection
ESX version
VNX software version
Recommended Native
Multipathing Plug-in path PSP
ESX 5.1
05.31.000.5.726 or later
Round-Robin
ESX 4.x
05.31.000.5.726 or later
Round-Robin or Fixed
Any release of ESX
Elias MR2 SP3 or earlier
Round-Robin or Fixed
VNX array software Elias MR2 SP4 contains an enhancement that allows the Round-Robin
Native Multipathing Plug-in PSP to auto restore to the preferred (default) VNX SP after the
preferred SP reboots, whether the reboot is manual, due to failure, or is part of an array
software upgrade (non disruptive upgrade [NDU]).
With ESX 5.1 and VNX OE for Block 05.31.000.5.726 or later, Round-Robin is the preferred
PSP for VNX LUNs. This environment provides the benefits of multiple active/optimized
paths for I/O scalability and auto restore to the preferred SP after any fabric failure or SP
reboot.
Use Round-robin when using Native Multipathing Plug-in.
Third-party multipathing - EMC PowerPath Virtual Edition
EMC provides a multipath plug-in called PowerPath Virtual Edition (PowerPath/VE) to
enhance the reliability and I/O efficiency of ESXi environments. PowerPath provides the
most comprehensive multipathing solution for vSphere environments.
PowerPath/VE is supported for all SCSI device configurations and offers the following
benefits:
◆
Performs adaptive load-balancing and path optimization.
◆
Performs proactive monitoring of I/O path for health status.
◆
Contains an intuitive CLI that provides end-to-end viewing and reporting of the host
storage resources, including HBAs.
◆
Applies policy changes at the host level.
◆
Uses auto restore to restore LUNs to the optimal SP after NDU or environmental failure
to ensure load balancing and performance.
◆
Provides the ability to balance queues on the basis of queue depth and block size.
Note: PowerPath provides the most robust functionality and is the recommended
multipathing option for VNX.
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VSI: Path Management
The Path Management feature is a feature of VSI that simplifies the LUN path policy
configuration. Figure 29shows how administrators assign global Native Multipathing
Plug-in or PowerPath path configuration preferences to VNX LUNs and maintain consistent
policies across all hosts in a virtual data center.
Figure 29 VSI Path Management feature
Use the VSI: Storage Viewer feature or the vCenter device properties to verify the existing
multipath policy for each LUN (Datastore).
Figure 30 illustrates the LUNs properties page within Storage Viewer. This view includes
the pluggable storage architecture that owns the LUN and the current PSPs. Use the VSI
Path Management feature to modify these properties if required.
Figure 30 Storage Viewer LUNs view
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Configuring VMware vSphere on VNX Storage
Note: Individual path modification must be done through vCenter or with the vSphere
command line utilities.
Multipathing considerations for NFS
ESXi hosts access NFS servers using NFS version 3 (NFSv3). The NFSv3 protocol is limited
to a single TCP session per network link. Therefore, the only way to balance the I/O load
for NFS is to use the physical layer to mount the NFS file system on different ESXi source
interfaces and different destination interfaces on the Data Mover. Configure multiple Data
Mover interfaces and distribute NFS TCP sessions between different source and
destination network interfaces. The default number of NFS mounts in ESXi4 and ESXi5 is
eight and 64, respectively. The number reaches a maximum value of 64 after the
NFS.MaxVolumes parameter on the host is modified. Elements of a multipathing
configuration for NFS illustrates the recommended configuration for high availability and
load balancing. Use the following guidelines to achieve high availability and load
balancing for NFS:
◆
Ensure that no single points of failure are at the physical network layer (NIC ports,
switch ports, physical network switches, and VNX Data Mover network ports).
◆
Balance the workload among all available I/O paths.
◆
Data Mover network ports, connections to switch - configure Link Aggregation on VNX
Data Movers and network switches for fault tolerance of network ports. LACP supports
load balancing among multiple network paths. Configure the Data Mover and ESXi
switch ports for static LACP.
Note: When a Cisco Nexus 1000v pluggable virtual switch is used on the ESXi hosts,
configure dynamic LACP for the ESXi and Data Mover NIC ports.
◆
ESXi NIC ports—NIC teaming provides physical network fault tolerance and load
balancing for ESXi hosts. Set the NIC teaming load balancing policy for the virtual
switch to Route based on IP hash for LACP configurations.
◆
Physical network switch—Use multiple switches and network paths for physical-layer
fault tolerance. Configure each Data Mover and ESXi host to use both switches. If the
switch supports Multichassis Link Aggregation, configure it to span the switches and
offer redundant port termination for each I/O path from the Data Mover and ESXi host.
Note: Use Fail-Safe Network on the VNX Data Movers with switches that do not support
Multichassis Link Aggregation technology.
Configure multiple network paths for NFS datastores
This section describes how to build the configuration shown in Figure 31.
Create a single LACP network device for the Data Mover through the Unisphere
Management UI. LACP devices use two physical network interfaces on the Data Mover and
two IP addresses on the same subnet.
Ensure that Link Aggregation is enabled on the switch ports, VNX Data Mover, and ESXi
network interfaces. Complete the following steps in EMC Unisphere and the vSphere Client
to create the multipath NFS configuration:
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Figure 31 Elements of a multipathing configuration for NFS
1. Log in to Unisphere.
2. Select the VNX system to manage. Select Settings > Network > Settings For File. The
Settings For File window appears as shown in Figure 32.
Figure 32 Unisphere interface
Unified storage considerations
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Configuring VMware vSphere on VNX Storage
3. Select the Devices tab, and then click Create. The Network Device dialog box appears.
a. In the Device Name field, specify a name for the LACP device.
b. In the Type field, select Link Aggregation.
c. In the 10/100/1000/10000 ports field, select two unused Data Mover ports.
d. Click OK to create the LACP device.
4. From the Settings For File window, select the Interfaces tab.
5. Click Create to create a new network interface.
Figure 33 Data Mover link aggregation for NFS server
6. Complete the following steps:
a. From the Device Name list box, select the LACP device that was created in Step 2.
b. Enter the IP address for the first Data Mover LACP interface.
c. In Data Mover link aggregation for NFS server, ensure that the IP address is set to
10.244.156.102 and the interface name is set to DM2_LACP1.
7. Click Apply to create the first network interface and keep the Create Network Interface
window open.
8. In the Create Network Interface window, type the details for the second network
interface. This information is identical to the information provided in Step 5 with the
exception of the IP address.
a. Type the IP address for the second LACP connection.
b. Click OK to create the second network interface.
9. Login to the vSphere Client and complete the following steps for each ESXi host:
a. Create a vSwitch for all the new NFS datastores in this configuration.
b. Create a single VMkernel port connection in the new vSwitch. Add two physical
NICs to it and assign an IP address for the VMkernel on the same subnet as the two
Data Mover network interfaces.
In Data Mover link aggregation for NFS server, ensure that the VMkernel IP address
is set to 10.244.156.183, with physical NICs VMnic0 and VMnic1 connected to it.
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c. Click Properties. The vSwitch1 Properties dialog box, vSphere networking
configuration, appears.
Figure 34 vSphere networking configuration
d. Select vSwitch, and then click Edit. The VMkernel Properties window appears as
shown in Figure 35.
Figure 35 VMkernel Properties window
e. Select the NIC Teaming tab, and in the Load Balancing list box, select Route based
on IP hash.
Note: The two VMnics are listed in the Active Adapters list for the NIC team. If the
corresponding switch ports are enabled for EtherChannel, network traffic is
statically balanced by using a unique hash value derived from the source and
destination IP addresses. As a result, the host will distribute network packets
between the VMkernel and Data Mover network interfaces to provide distribution
of I/Os among the available network paths, and yield a higher throughput.
Unified storage considerations
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Configuring VMware vSphere on VNX Storage
f. Use the VSI: Unified Storage Management feature to provision NFS datastores.
i. From the Data Mover Name list box, select the primary Data Mover.
ii. From the Data Mover Interface list box, select the IP address of the first network
interface that was created.
g. Create and distribute the virtual machines evenly across datastores, or use SDRS
to automate the virtual machine placement within the datastore cluster.
vSphere storage considerations
Up to this point, this chapter has presented the configuration options for host connectivity
and automated storage provisioning using EMC's management features. This section of
the paper describes vSphere storage related features and identifies considerations for
using them with VNX storage. Some of these features are version specific, as indicated.
Dead space reclamation (Unmap)
Release 5.0 U1 introduced a feature called dead space reclamation to reclaim disk space
when a file or virtual machine is deleted or moved off a thin VMFS datastore.
Unmap works with VMFS datastores provisioned using VNX thin LUNs.
Most environments are dynamic: virtual machines, virtual disks, and files are added,
removed, and migrated within VMFS datastores. After a file is deleted or migrated, the
ESXi host de-allocates the disk blocks within the VMFS file system. However, those blocks
are still allocated within the VNX LUN and are reusable only by virtual machines that share
the same VMFS datastore.
Dead space reclamation provides a manual method to instruct the thin LUN to release the
allocated blocks and return the unused space to the global storage pool so that it can be
used by other datastores or RDM LUNs.
In ESXi 5.1, the unmap process is initiated through an extension to the vmkfstools.
Passing the -y argument with a numerical value instructs the ESXi host to perform an
UNMAP command on the corresponding VNX device.
The unmap command is contextual, which means it must be run from the command of the
ESXi host and the current directory must be within the directory path of the datastore. The
numerical value provided to the -y argument is the percentage of allocated space that you
intend to reclaim.
When the command is initiated, the ESXi host creates a balloon file within the datastore
and issues SCSI UNMAP commands (0x42) to the VNX SCSI target to release the LUN
blocks that correspond to the freed blocks within the VMFS datastore. Freeing the space
within the thin LUN returns the slices to the storage pool.
Note: This process does incur overhead that could impact other systems. It should be run
during a maintenance window.
In Figure 36, two LUNs, named Thin and Thick to identify the device type, exist within a
VNX storage pool (Pool 0). The thick provisioned LUN is 100 GB in size and the disk slices
associated with it are persistently reserved within the pool when the LUN is created. Those
blocks are not released to the pool until the LUN is deleted.
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The second LUN, called Thin, is 300 GB in size. However, since it is thin provisioned,
approximately 2 GB of metadata is allocated from the storage pool. After formatting the
VMFS volume, the total slice allocation within the pool is 114 GB.
In step 2 of Figure 36, a virtual machine with a virtual disk of 40 GB is created and stored
on the thin LUN, resulting in 140 GB of allocated space within Pool 0.
Figure 36 Virtual machine configured on a Thick LUN
The top half of Figure 36 illustrates what happens when the virtual machine is migrated
from the thin LUN datastore to the thick LUN datastore. The space within each datastore
changes, but the thin pool utilization remains the same.
In the example the ESX host command line was used to change directory to the
/vmfs/volumes/Thin directory where the vmkfstools command was run with the (-y) and
99 percent arguments. The result is seen in the bottom half of the screen, illustrating that
the space was restored to the VNX pool.
Use the vmkfstools command to reclaim unused space within ESXi datastores provisioned
from thin LUNs. The example in Figure 37 illustrates how to identify the space.
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Note: The vSphere/ESXi5.5 release provides the unmap control through the esxcli utilities.
The syntax for that command is
# esxcli storage vmfs unmap -I (datastore UUID) -n (# blocks to
free)
Figure 37 Virtual machine migrated to a thin LUN
VMFS-5
In vSphere 5,VMware introduced a new version of the VMware file system. VMFS-5
provides improved scalability, and interoperability with storage systems with the following
properties:
◆
Support for larger file systems and volumes.
◆
Fixed block size of 1 MB.
• Eliminates the 1, 2, 4 MB block sizes required to support larger files in previous
releases.
• Supports double- and triple-block indirect pointers for larger files.
◆
Atomic Test and Set (ATS/Hardware Accelerated Locking) is enabled for all SCSI
devices.
• ESXi hosts always attempt to use ATS on VMFS-5 volumes.
• If an ATS operation fails, the LUN processes the request using SCSI-2 commands.
Subsequent requests revert to ATS.
• Small block allocation configurations.
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Datastores created with vSphere 5 use the VMFS-5 format; however, VMFS-3 is still a
supported option. Although the preceding list may not seem extensive, VMFS-5 volumes
should be used for all new datastores.
An option to perform an upgrade from VMFS-3 to VMFS-5 through vmkfstools is provided;
however, upgraded VMFS-3 file systems do not take advantage of all VMFS-5 features.
The limitations of upgraded VMFS-3 datastores are that they:
◆
Use the VMFS-3 block sizes, which might be larger than the unified 1 MB file block
size.
Note: VAAI Full Copy operations are not supported between datastore volumes that
are formatted with different block sizes.
◆
Use 64 KB sub-blocks instead of the new 8 K sub-blocks.
◆
Have a file limit of 30,720 instead of the file limit of > 100,000 for new VMFS-5
datastores.
Instead of upgrading from VMFS-3 to VMFS-5, create a new VMFS-5 volume and migrate
the virtual machines with Storage vMotion. Use VNX thin-provisioned LUNs in conjunction
with VMware thin virtual disks to reduce the amount of storage space required to perform
this task.
vStorage API for Array Integration
VAAI storage integration improves ESXi host resource utilization by off loading
storage-related tasks to the VNX. The storage system performs the select storage tasks,
freeing host resources for application processing and other tasks.
Storage vMotion is a core feature of SDRS in vSphere 5 that takes advantage of the
capabilities of VAAI. During a Storage vMotion task, the ESXi host issues SCSI extended
copy (XCOPY) commands that include the source and destination block address
information required for the VNX to perform the block copies. The commands include the
information required for the VNX to copy the data blocks from the source LUN to the target
device.
With VNX OE for Block version 5.32 and VNX, VAAI is executed in less time and consumes
significantly fewer CPU, memory, and SAN I/O resources than when the task is executed
on the host.
The primary VAAI functions are:
◆
Hardware Accelerated Zeroing (Block Zero)—Uses SCSI WRITE SAME commands to
initialize blocks on a virtual disk. It is used to zero out newly created virtual disks
during new virtual disk or virtual disk clone tasks. When a thick eager zeroed virtual
disk is created, this primitive feature creates the virtual disk file and rapidly initializes
all of the blocks.
◆
Hardware Accelerated Locking (Atomic Test and Set [ATS])—Alleviates VMFS
contention resulting from metadata operations such as virtual disk creation and
virtual machine boot. ATS provides extent-level locking to the VNX LUN, which enables
metadata updates without locking the entire device. ATS alleviates contention during
boot storms and other vSphere operations that require considerable metadata
updates.
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◆
Hardware Accelerated Copy (Full Copy)—Uses SCSI XCOPY commands to perform block
movements within the array. The primitive is initiated by vSphere Clone, Storage
vMotion (SDRS), and Deploy Virtual Machine from Template tasks.
◆
NFS Clone Offload—Off loads ESXi clone operations to the VNX Data Mover. This
produces results similar to those for Hardware Accelerated Copy. The ESXi host
achieves a reduction in CPU and network resource utilization.
VAAI improves host efficiency by using host CPU, memory, and SAN to satisfy application
servers. They enable dense datastore configurations with improved operational value.
With the exception of NFS, ESXi hosts use these features by default. Use these features
with VNX storage.
EMC NAS plug-in for NFS
vSphere 5.0 and later versions provide support for VAAI operations on NFS datastores.
Working in conjunction with storage vendors such as EMC, VMware has integrated VAAI
with VNX through a software interface installed on each ESXi host. With this software or
host plug-in installed, ESXi hosts can use the VNX Data Mover to perform the tasks listed
in NFS VAAI features.
VMware View 5.1 provides the ability to deploy new virtual machines using VNX Fast
Clones. The View 5.1 product uses the NFS plug-in to create thin virtual disks within the
virtual machine directory on the NFS datastore.
Table 4 provides a list of the NFS VAAI features.
Table 4 NFS VAAI features
Feature
VNX OE
Full clone
7.31 and later
Extended stats
7.31 and later
Space reservation
7.31 and later
Snap of snap (VMware Tech Preview in
View 5.1)
7.31 and later
Virtual machine clones
VAAI for NFS leverages the VNX Data Mover to create thin fast-clone replicas and thick
full-clone replicas of virtual machines on the NFS datastores. Thin clones are created
instantaneously using a few file system blocks that reference the original virtual machine
data. This option preserves space by using a single image. All of the virtual disk blocks
that make up the virtual machine exist as references to the source virtual machine. The
exception is in modified data that allocates additional blocks within the file system as
needed.
When creating full clones, the VNX Data Mover/X-Blade creates an exact replica of an
existing virtual machine using an identical amount of storage as the source virtual
machine.
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Nested clones (snap-of snap)
VNX File OE version 7.1 and later versions include a VAAI capability to create a thin-clone
virtual machine from an existing thin clone virtual machine. This functionality is referred to
as nested clones or snap-of-snap. The functionality uses the VNX snapshot architecture to
instantaneously create lightweight virtual machine clones. VMware products such as View
Composer and vCloud Director use View Composer Array Integration (VCAI) to initiate
virtual machine clones using the VNX Data Mover API for nested snapshots. The clone
operations are off loaded to the VNX Data Mover. To take advantage of this feature, enable
the nested clone support property when you create the file system.
Figure 38 Create File System
EMC NAS plug-in installation
EMC provides a software module or plug-in to enable VNX NFS VAAI functionality on ESXi
hosts. The software is provided as a VMware installation bundle (VIB) that is installed
through the command line of the ESXi host or through VMware vCenter Update Manager.
Figure 39 illustrates the esxcli command issued to install the VIB after copying it to the
/tmp directory of the ESXi host. Place each host in maintenance mode before installing the
plug-in.
Figure 39 Plug-in installation
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vCenter displays the Hardware Accelerate property of the NFS datastores in the
Datatstores tab, illustrated in Figure 40.
Figure 40 NFS Hardware Accelerate datastore property
If the VNX NFS datastore property is not set to Supported, run the following command on
the ESX host to verify that the plug-in is correctly installed:
esxcli software vib list | grep EMCNasplugin
Vmkfstools extended stats
vSphere 5 includes additional vmkfstools command-line arguments to display the disk
utilization for virtual machine disks configured on NFS datastores. The extendedstat
argument provides disk details for the virtual disks using NFS storage. The command
reports virtual disk size, used space, and unshared space. The -extendedstat argument
reports all values in bytes, as shown in Figure 41. This helps when creating automated
reports or custom provisioning scripts.
Figure 41 Vmkfstools disk utilization option
Storage Distributed Resource Scheduler
SDRS is a vSphere 5 feature that provides the ability to group multiple datastores into a
single managed storage object called a datastore cluster. The cluster is integrated into
vCenter management storage devices as a storage abstraction with some of the same
placement and migration capabilities that make SDRS so valuable for CPU and memory. It
allows VMware administrators to manage storage as a pool of resources or datastore
cluster instead of a series of individual datastores.
SDRS relies on a new storage object called a datastore cluster. These clusters consist of
multiple VMFS or NFS datastores, as shown in Figure 42.
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An SDRS cluster is configured by adding existing VMFS or NFS datastores; however, each
cluster must contain either NFS or VMFS volumes, but not both, in the same cluster.
Clusters are resized quickly by adding or removing datastores through vCenter SDRS
management.
Datastore clusters can include LUNs from multiple VNX systems, although this is not
recommended. VAAI only works with LUNs accessed from the same storage system. The
lack of VAAI support affects the performance of Storage vMotion if LUNs reside on different
systems.
Figure 42 SDRS datastore cluster
SDRS monitors the capacity and response time of each datastore within the cluster. It
applies policy rules to determine the initial placement and relocation of virtual machines
within the clustered datastores.
Virtual machine placement simplifies resource planning, which has traditionally required
performance monitoring and analysis. Instead of running tools to identify hot spots and
perform manual migrations, create an SDRS cluster. Use datastores with similar
performance characteristics and establish a policy to specify capacity and latency
requirements for virtual machine disks. SDRS will continuously monitor the storage
resources and provide recommendations to distribute the virtual machines between the
datastores.
Relocation moves the virtual machine from the existing datastore to one of the other
datastores in the cluster. SDRS relocation recommendations can be configured for manual
or automated execution.
SDRS monitors available capacity (free space) and, optionally, device latency for each
datastore within the cluster. SDRS makes recommendations for virtual machine relocation
when:
◆
An individual datastore exceeds its defined capacity threshold.
◆
A change occurs in the environment.
◆
The administrator selects the SDRS button.
◆
A capacity- or service-level imbalance exists between the datastore where the virtual
machine resides and another datastore in the cluster.
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SDRS is not meant to be a highly reactive solution. It can be tuned for aggressive
relocations, but the default relocation policy requires 8 to 24 hours of activity. SDRS
continuously collects datastore capacity and, optionally, I/O latency information. At
user-defined intervals, the datastore information is assessed against existing policy rules
to determine if virtual machine relocation is warranted.
Note: VNX FAST VP is also a periodic task that can be automated or run manually to
rebalance the blocks within a pool LUN. The two features work together; however, do not
use FAST VP relocation when SDRS I/O metrics are in use. Disable I/O metrics on FAST VP
LUNs.
SDRS policy configuration
SDRS provides the following automation policies, as shown in Figure 43:
◆
Fully Automated—Performs initial placements and virtual machine relocation without
user intervention
◆
No Automation—Presents a recommendation each time a virtual machine relocation is
triggered
Figure 43 SDRS advanced policy configuration
Policy metrics are:
78
◆
Utilized Space—Amount of space consumed within a datastore. The default value for
this parameter is 80 percent. This means that SDRS does not evaluate migration
policy until the datastore exceeds that capacity threshold.
◆
I/O Latency—Datastore response time measured in milliseconds. The default value is
15 ms. SDRS does not evaluate migration policy until the datastore exceeds a 15 ms
response time and the imbalance rules are also satisfied.
Using EMC VNX Storage with VMware vSphere TechBook
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◆
Imbalance timer value—Interval for applying the SDRS policy to the datastore cluster.
The default value is eight hours. vSphere collects data at standard intervals and
reconciles resource utilization every eight hours.
Do not complete latency assessments for FAST VP LUNs, because variability in the
application workload can distort the results. SDRS and FAST VP perform a similar function,
although at a different level of granularity, to rebalance resources. Use either SDRS or FAST
VP for workload rebalancing across storage resources. Do not use both services at the
same time.
Figure 44 shows the interface to disable I/O metrics and apply policy based on capacity
utilization. Clear the check box for enabling I/O metrics for SDRS recommendations.
Figure 44 SDRS I/O metric enablement setting
Notes:
◆
SDRS I/O load balance does not work if the datastore cluster is not configured for all
hosts that share the datastores.
◆
VAAI operations do not span storage systems. The host processes migrations of
virtual machines between clustered datastores from different storage systems.
VNX storage recommendations for SDRS
Create a datastore cluster from LUNs that have similar storage characteristics such as
capacity, drive type, latency, and tiering policy. This configuration allows SDRS to evenly
balance virtual machine capacity and I/O requirements.
When VASA and virtual machine storage profiles are configured, each datastore must have
the same capability for automated migrations and virtual machine evacuations.
Avoid using LUNs from the same RAID group or storage pool within an SDRS cluster. The
intent of SDRS is to distribute the I/O between the storage resources within VNX. Creating
multiple LUNs from the same RAID group results in their sharing the same set of spindles,
which could negate the benefits to SDRS. The following list identifies several actions to
complete for SDRS:
◆
Use LUNs of equal size and storage type.
◆
Add LUNs in pairs and distribute LUN ownership between the VNX storage processors.
◆
Disable I/O metrics when using FAST VP pool LUNs.
◆
Set migration policy to manual when using FAST VP configurations.
◆
Configure the migration policy to manual mode until you have assessed the
environment for a period of time.
◆
Assign multiple Storage vMotion connections to reduce migration times.
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◆
Do not use SDRS with datastore LUNs that are protected with VNX synchronous
replication technologies such as MirrorView.
◆
Virtual machine relocations can significantly impact synchronous replication. To use
synchronous replication, set the SDRS migration policy to manual to limit
unnecessary data replication from virtual machine migration.
Table 5 shows supported SDRS LUN configurations.
Table 5 Supported SDRS LUN configurations
VNX feature
Initial placement
Migration recommendation
Thin, Thick, FLARE LUN
X
X
FAST VP
X
No, manual mode
FAST Cache
X
No, manual mode
Replication
X
No
LUN sanpshots
X
No
Dedupe
X
No
Thin
X
Supported with VASA
vStorage API for Storage Awareness
VASA, introduced in vSphere 5.0, is implemented as a vCenter service that communicates
with the storage system to discover the storage capabilities of the VNX devices. vCenter
presents these storage capabilities in various management interfaces related to
datastores, datastore clusters, and virtual machine disks. Figure 45 illustrates the storage
capabilities of a datastore cluster using SAS drives with Fast Cache enabled for the LUN.
Figure 45 VASA datastore storage capability of VNX Flash drive LUN
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Awareness of the storage capabilities of each datastore allows the vSphere administrator
to make informed decisions when performing administrative tasks. For example, knowing
that the target datastore for a virtual machine migration has the same capabilities as the
source ensures that the task does not impact the virtual machine service level.
Additionally, virtual machine storage profiles use storage capabilities to identify
appropriate datastores for Storage vMotion operations.
VNX OE for Block provides native VASA support in versions 5.32 and later. In versions prior
to 5.32, VASA support is provided through the EMC Solutions Enabler VASA Provider.
The initial VASA release included a basic set of properties to identify the capabilities of
each LUN. Support for VNX File OE was unavailable prior to release 7.1. Table 6 lists
capabilities for the initial implementation.
Table 6 VASA storage capability mapping to VNX LUNs
VNX LUN type
vCenter storage capability
FLARE SAS LUN
Capacity
FLARE SSD LUN
Extreme performance
Pool LUN
Multitier storage
Fully Automated Storage Tiering LUN Multitier storage
FAST Cache LUN
Multitier storage
NFS export
Unsupported
The VASA service is provided through the VNX storage processor and Control Station.
When using VASA on a VNX OE for Block version 5.32 or later, configure the vCenter VASA
service with direct access to the VNX controllers.
Datastore capabilities are reported based on the device type used to create the datastore.
The disk properties are listed in column 1 of Table 7 as SAS, NL-SAS, Solid State, or
Automated Storage Tiering when the LUN is created from multiple disk types using VNX
FAST VP technology.
Additional properties of the device are appended to the basic storage element to
differentiate the capabilities. Those are listed in the LUN properties column. The end
result as shown in VASA datastore storage capability of VNX Flash drive LUN is that the
LUN will include a single storage type and can include zero or more properties.
For example, a SAS RAID group LUN without FAST Cache enabled has a storage capability
of SAS/Fibre Channel.
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Table 7 shows that a thin pool LUN with mixed drive types has a storage capability of
Automated Storage Tiering, Thin Pool LUN.
Table 7 VNX OE for Block 5.32 storage capability mapping to VNX LUNs
VNX LUN type
LUN properties
vCenter filters include one or more
item listed below
VNX Block Provider
NL-SAS/SATA
SAS/Fibre Channel
Solid State
Auto-Tier
FAST Cache enabled
LUN Replication
LUN Compression
Thin Pool LUN
FAST Cache
Remote Replication
Space Efficiency
Thin
VNX File Provider
NL-SAS/SATA
SAS/Fibre Channel
Solid State
Auto-Tier
FAST Cache enabled
File Replication (RepV2)
File Dedeuplication
Thin Pool LUN
FAST Cache
Storage Efficiency
Thin
Replication
Virtual machine storage profiles
Virtual machine storage profiles provide the ability to associate each virtual machine disk
with a particular storage capability. Virtual machine storage profiles are defined by
associating the profile with one or more VNX storage capabilities. Figure 46 shows a new
user-defined profile name called SAS Fibre FAST Cache. This profile includes all SAS LUNs
that have FAST Cache enabled and no other LUN capabilities enabled. All datastores that
possess the SAS and FAST Cache capabilities are candidates for virtual machine disks that
are assigned to this storage profile.
Note: A storage capability can be assigned to multiple storage profiles. Use caution when
creating new profiles to ensure that the policy performs as intended.
Figure 46 Storage profile assignment
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Virtual machine storage profiles are assigned to each virtual disk. They enforce virtual disk
to datastore compliance, and virtual disk migration for tasks such as Storage vMotion.
When a migration or Storage vMotion is initiated, the migration wizard identifies the
datastores that are compatible for the current virtual machine storage profile.
In Figure 47, two datastores are compatible with the SAS Fibre storage profile. In this
example, both datastores are using SAS disks; however, one is an NFS datastore and the
other is a VMFS datastore. The VASA service highlights the recommended datastore, but
presents both as compatible options. Use the Type field in the list to identify the transport
protocol and ensure that the correct one is selected.
Figure 47 Compatibility/incompatibility with SAS Fibre storage profile
Virtual machine storage profiles are also used by datastore clusters when SDRS is
enabled. SDRS controls virtual disk placement and uses profiles for migrations and
evacuations when a datastore is placed in maintenance mode.
Note: If SDRS and Storage Profiles are used, ensure that the datastores support the
storage capabilities; otherwise, automated migrations might not work correctly.
User-defined storage capabilities
n some cases, VASA does not have a profile that matches the properties of a datastore or a
need exists to define a profile for specific datastores in the environment. For example,
vSphere 5.0 and VNX OE for Block version 5.31 provide a limited set of VMFS capabilities
and do not support NFS datastores. Create a user-defined profile to use storage profiles.
To configure a user-defined storage profile for NFS datastores from VNX storage:
1. Log in to vSphere and select the VM Storage Profiles icon.
2. Enable virtual machine storage profiles for the hosts in the cluster:
a. Select Manage Storage Capabilities.
b. Add a storage profile with a user-defined name.
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Figure 48 Enabling virtual machine storage profiles
3. Add a virtual machine storage profile.The virtual machine profile can use the same
name as the storage profile.
4. Select the user-defined storage profile from step 2 to associate the virtual machine
profile with the storage profile.
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5. Assign the new profile to existing datastores.as shown in Figure 49. and Figure 50.
Figure 49 Associating datastores with a user-defined storage profile
Figure 50 Associating the virtual machine with a user defined storage capability
6. Associate the virtual machine virtual disks with this profile to ensure compliance.
7. Introduce this profile as part of the virtual machine storage management tasks.
vCenter storage provider configuration
VASA runs as a client service called vSphere Profile-Driven Storage on the vCenter server.
The service interacts with an EMC provider running on either a Windows system running
Solutions Enabler, the VNX storage processor, or on the VNX Control Station.
Note: VNX OE for Block version 5.31 requires an SMI-S proxy service to communicate with
the storage processor. Install and configure the EMC VASA provider on a Windows system
or deploy the VASA provider virtual appliance. The Windows system can be the same host
that runs vCenter or a stand-alone system.
The vSphere storage provider communicates with the EMC provider over secure http and
an administrative SMI-S-authorized user account.
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To configure the vCenter VASA service:
1. Select the Storage Providers icon in the vSphere management screen to open the
configuration interface illustrated in Figure 51.
Figure 51 VASA configuration
2. Click Add to configure the vCenter VASA service with an existing EMC SMI-S VASA
provider service that is configured to monitor the VNX system in the vSphere
environment.
3. Provide the following information to assign the new service in the vSphere Client to an
SMI-S Server:
• User-defined name
• VASA Service Uniform Resource Locator on the SMI-S system in the following
format:
https://<smi_server_name>:5989/vasa/services/vasaService
• Login credentials for the SMI-S service: These are the credentials defined for the
VASA service within SMI-S.
VNX OE for Block version 5.32 and later have embedded the Block provider onto the
storage processor. A File provider is available on the VNX Control Station for File and
Unified systems. With the release of version 5.32, an external SMI-S service is not
required. Configure the VASA service to communicate directly to the storage processor for
block, and the Control Station for file. This service does not require an external SMI-S
server. As of VNX OE for File 7.1, the Control Station supports a VNX Provider for File
storage.
VNX OE for Block version 5.32 and VNX OE for File version 7.1 environments use the
following URL syntax and the IP address of the storage processor.
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◆
SP configuration
• https://<storage processor IP Address>/vasa/services/vasaService
• Login credentials for the Control Station:
– user id: vmadmin
– password: <vmadmin password>
◆
Control Station configuration
• https://<Control Station IP address>:5989/vasa/services/vasaService
• Login credentials for the Control Station:
– user id: vmadmin
– password: <vmadmin password>
Storage I/O Control
SIOC offers storage resource management capability for virtual disks and datastores. It
provides a way to govern virtual disk utilization within a clustered datastore. SIOC uses
virtual machine disk shares and disk IOPS settings to establish precedence, and
apportions the virtual machine storage resources when the datastore response time
exceeds predefined levels.
SIOC can be used along with FAST VP.
Virtual machine disk shares are assigned when the virtual disk is created. The default
share value is normal or 1,000 shares. It is customizable, with settings of low (500) and
high (2,000) share values. SIOC works at the host and cluster level. It aggregates the
virtual disk share values of all powered-on virtual machines on the host and uses that
value as a percentage of all other host disk shares when it needs to throttle the device
queue among hosts in the cluster.
Figure 52 Virtual disk shares configuration
SIOC uses a latency value called a congestion threshold. This value, specified in
milliseconds (ms), defines the acceptable latency of the device that supports the
datastore. Valid settings range from 5 ms to 100 ms. 30 ms is the default value.
The appropriate congestion control value for a datastore depends on multiple factors:
◆
Type of device
◆
Number of disks supporting the LUN
◆
Other consumers of the spindles
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Define an IOPS limit per virtual machine to avoid a situation where a single virtual
machine monopolizes the datastore. For example, limit the amount of IOPS per virtual
machine to 1,000.
Table 8 lists the recommendations for setting the congestion threshold.
Table 8 SIOC congestion windows
Datastore storage type
Congestion window (ms)
Notes
Enterprise flash drive
10-20
SAS drive
20-30
NL-SAS
35-50
FAST VP/Tiered LUN
35-50
View the storage distribution within
the pool
NFS
30
• Response time includes any
latency that exists in the network.
• Increase the congestion window
by any latency that exists in the
network.
Note: SIOC detects workloads on a shared storage device that are external to VMware. If
the SIOC LUN is accessed for some other purpose, such as replication or storage system
cloning, ESXi generates an error that states that an external workload is detected.
Unmanaged I/O workload detected on shared datastore running Storage I/O Control
(SIOC) for congestion management (1020651), available in the VMware Knowledge base,
provides more information.
SIOC for NFS
vSphere 5.0 and later versions provide SIOC support for NFS datastores mounted on ESX
host clusters. SIOC for NFS uses the same framework as VMFS by applying a synthetic
queue depth for NFS file systems. The SIOC driver throttles I/O by adjusting the host
queue depth to the NFS datastore file systems when contention is encountered. Each
configured datastore inherits a default host response time value of 30 ms.
Figure 53 NFS SIOC congestion window
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Notes:
◆
NFS datastore response time includes network latency. Ensure the IP storage network
does not contribute latency of more than a few milliseconds, or adjust the congestion
threshold setting for network overhead.
◆
Workloads that compete for the NFS datastore I/O can impact SIOC. Do not share the
NFS datastore or file system disks.
Network considerations
The VNX platform supports a wide range of network topologies and capabilities for
VMware vSphere. This section lists items to consider when planning an IP storage network
for vSphere servers.
Network I/O Control
vSphere Network I/O Control (NIOC) provides a way to manage and prioritize network
resources at the cluster level. NIOC is an advanced networking feature of vNetwork
distributed switches for vSphere 4.1 and later versions.
vNetwork distributed switches provide an efficient way to centralize, manage, and share
datacenter network resources. NIOC enables the virtual administrator to classify network
traffic. Each network type is configured with a share value which applies a weighting factor
to prioritize network traffic.
Figure 54 shows that NIOC has several default network classes that enable finer control of
the network resources within each network resource pool. A throughput value can also be
assigned to limit the resource utilization in Mb/s for each host that shares that resource.
Figure 54 Network Resource Allocation interface
The ability to adjust network prioritization offers some flexibility to tune the network for
particular applications. With the trend toward converged networks, NIOC provides the
ability to establish fairness for storage and virtual machine network adapters. Monitor the
environment to ensure that the VMkernel resources are set to normal or high, and are not
artificially limited by the network resource pool configuration.
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LUN removal (All Paths Dead)
Prior to vSphere 5, a condition known as All Paths Dead (APD) occurs when an ESXi host
loses access to a shared storage device. The device loss can be due to a temporary
environmental issue such as a switch failure, or an administrative action such as removing
a LUN from a storage group. In ESXi releases prior to ESXi 5, the host could not
differentiate between these two states.
In ESXi 5 and later versions, the VMkernel performs additional SCSI commands to detect
the state of the device and determine whether a device is in an All Paths Dead state or a
Permanent Device Loss (PDL) state.
All Paths Dead results when none of the HBAs on an ESXi host can establish a session with
the VNX SCSI target that supports the datastore LUNs. In this state, the host continues to
retry the connection for a period of time before marking the device unavailable.
PDL is a different state in which the host initiator has an active session with the SCSI
targets on the storage processor. The host issues SCSI commands to the target and uses
the SCSI sense codes returned by the VNX to determine the state of the missing device. If
the host determines that the device is removed, it flags the device as PDL and performs
the necessary steps to clean up the vCenter storage objects that were dependent on the
storage device.
vSphere does not remove virtual machines that were stored within a datastore on the
missing LUN. If a LUN is blindly removed, the virtual machines remain in an orphaned
state.
To prevent orphan virtual machines, vSphere 5 provides a datastore workflow option to
detach or unmount a datastore from the host, as illustrated in Figure 55.
The feature provides a graceful device removal and ensures that the datastore removal
does not violate any dependent relationships between the virtual disks and the datastore.
Remove the device from the host storage group in vSphere after it is detached or
unmounted.
Figure 55 vSphere 5 Datastore removal wizard
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Virtual machine considerations
Consider the following items to achieve optimal performance and functionality in virtual
machines on VNX storage:
◆
Virtual machine disk partition alignment
◆
Virtual machine swap file location
◆
Paravirtualized SCSI adapter (PVSCSI)
◆
N Port ID virtualization (NPIV)
◆
Virtual machine resiliency over NFS
Virtual machine disk partition alignment
The alignment of virtual machine disk partitions improves application performance and
the efficiency of the storage system. Because a misaligned disk partition in a virtual
machine can lead to degraded performance, align virtual machines that are deployed over
any storage protocol. The following recommendations provide the best performance for
the environment:
◆
Create the datastore in the vSphere Client or VSI Unified Storage Management.
◆
The benefits of aligning boot partitions are generally marginal. If only a single virtual
disk exists, consider adding an app/disk partition.
◆
It is important to align the app/data disk partitions that sustain the heaviest I/O
workload. Align the partitions to a 1 MB disk boundary in both Windows and Linux.
Note: Windows 2008, Windows Vista, and Windows 7 disk partitions are aligned to
1 MB by default.
◆
For Windows, use the allocation unit size recommended by the application. Use a
multiple of 8 KB, if no allocation unit size is recommended.
◆
For NFS, use the Direct Writes option on VNX file systems. This option helps with
random write workloads and virtual machine disks formatted with a 4 KB unit size
allocation.
◆
EMC also provides a free tool called UBERAlign that identifies and corrects misaligned
virtual disks. Everything VMware At EMC provides more information on this tool.
Align virtual machine disk partitions
The disk partition alignment within virtual machines is affected by a long-standing issue
with the x86 processor storage configuration. As a result, external storage devices are not
always aligned in an optimal manner. This is true for vSphere environments, in most
cases. The following examples illustrate how to align data partitions with VNX storage for
Windows and Linux virtual machines.
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Aligning Windows virtual machines
Note: This step is not required for Windows 2008, Windows Vista, Windows 7, and
Windows 8, which align partitions on 1 MB boundaries for disks larger than 4 GB (64 KB
for disks smaller than 4 GB).
To create an aligned data partition, use the diskpart.exe utility as follows; the example
assumes that the data disk to be aligned is disk 1:
1. At the command prompt, type diskpart.
2. Type select disk 1, as shown in Figure 56.
Figure 56 Select the disk
3. Type create partition primary align=1024 to create a partition to align to a 1 MB disk
boundary.
4. Type Exit.
Set the allocation unit size of a Windows partition
Use Windows Disk Manager to format an NTFS partition. Select an allocation unit that
matches your application needs.
Note: The default allocation unit is 4 KB. However, larger sizes such as 64 KB can provide
improved performance for volumes that store large files.
Aligning Linux virtual machines
Use the fdisk command to create an aligned data partition:
1. At the command prompt, type fdisk /dev/sd<x> where <x> is the device suffix.
2. Type n to create a new partition.
3. Type p to create a primary partition.
4. Type 1 to create partition number 1.
5. Select the defaults to use the complete disk.
6. Type t to set the partition system ID.
7. Type fb to set the partition system ID to fb.
8. Type x to go into expert mode.
9. Type b to adjust the starting block number.
10. Type 1 to choose partition 1.
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11. Type 2048 to set the starting block number to 2048 for a 1 MB disk partition
alignment.
12. Type w to write the label and partition information to disk.
Identify the alignment of virtual machines on Windows
Complete the following steps to identify virtual disk alignment:
1. From the Start menu, select Programs > Accessories > System Tools > System
Information.
The System Information window appears as shown in Figure 57.
Figure 57 Guest disk alignment validation
2. Locate the Partition Starting Offset property and verify the value is 1,048,576 bytes as
shown in Figure 58.
Figure 58 NTFS data partition alignment (wmic command)
This value indicates alignment to a 1 MB disk boundary.
Note: Type wmic partition get StartingOffset, Name at the command
prompt to display the partition starting offset.
Partition allocation unit size
Run the fsutil command to identify the allocation unit size of an existing data partition.
At the command prompt, type fsutil fsinfo ntfsinfo <drive_letter>.
The Bytes Per Cluster value identifies the allocation unit size of the data partition.
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Identify Linux virtual machine alignment
Run the fdisk command to identify the current alignment of an existing Linux data
partition. In Figure 59, /dev/sdb is a data partition that was configured on a Linux virtual
machine.
In the terminal session, type fdisk -lu <data_partition>.
Figure 59 Output of 1 MB aligned Linux partition
The unaligned disk shows the starting sector as 63, as shown in Figure 60.
Figure 60 Output for an unaligned Linux partition (starting sector 63)
Virtual machine swap file location
Each virtual machine is configured with a swap file that stores memory pages under
certain conditions, such as when the balloon driver is inflated within the guest OS. By
default, the swap file is created and stored in the same folder as the virtual machine.
When the swap file is stored on a SAN device it can have an adverse impact on virtual
machine performance if a lot of concurrent I/O results from paging activity.
Use proper virtual machine memory and resource configuration to avoid swapping. Do not
unnecessarily reserve or artificially cap memory resources for virtual machines. These
configurations contribute to swapping conditions.
The best way to avoid the impact of swapping is to use low latency, high throughput
devices such as local or SAN EFD storage. This alleviates the contention that results from
swapping activity.
It is possible to use a local device to off load up to 10 percent of the network traffic that
results from the page file I/O. The trade-off for moving the swap file to the local disk is that
it may result in additional I/O when a virtual machine is migrated through Storage vMotion
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or DRS. In such cases, the swap file must be copied from the local device of the current
host to the local device of the destination host. It also requires dedicated local storage to
support the files.
A better solution is to use high-speed, low-latency devices such as EFDs to support the
swap files.
If each virtual machine has 100 percent of its memory reserved from host physical
memory, it is possible to use SATA drives to support page files. Implementations for virtual
desktop environments are examples of this situation. Reserve the virtual machine desktop
memory to allow the applications and OS to take advantage of client-side caching by using
DD RAM within the ESXi host instead of the slower SAN storage. This approach yields
sustained application performance.
If this configuration option is unavailable, use EFDs for page files where performance is a
concern. vSphere 5 provides a feature called Host Cache to assist with the configuration of
virtual machine swap files with EFD storage.
Host Cache
vSphere 5 simplifies the configuration of virtual swap through a feature called Host Cache.
Host Cache recognizes EFD storage assigned to the host, and allows a portion of that
storage to be used to support virtual swap files. This feature configures virtual swap files
within the datastore and provides them to the virtual machine to complement the existing
swap configuration.
Figure 61 Host Cache configuration on VNX EFD storage
Paravirtual SCSI adapters
Paravirtual SCSI (PVSCSI) adapters are high-performance storage adapters that can
provide greater throughput and lower CPU utilization. PVSCSI is best suited for SAN
environments where hardware or applications drive very high throughput.
PVSCSI adapters combine I/O requests to reduce the cost of virtual interrupts. vSphere 4
Update 1 and later support the PVSCSI adapter for the virtual machine boot disk in
addition to virtual data disks.
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In tests run with Windows 2003 and Windows 2008 guest operating systems, the PVSCSI
adapter has been found to improve the resiliency of virtual machines running on
NFS-based storage.
The following guest operating systems support the PVSCSI adapters:
◆
Windows Server 2003 and 2008
◆
Red Hat Enterprise Linux (RHEL) 5
PVSCSI adapters have the following limitations:
◆
Hot-add or hot-remove requires a bus rescan from the guest.
◆
PVSCSI may not provide performance gains when the virtual disk has snapshots, or
the ESXi host memory is overcommitted.
◆
If RHEL 5 is upgraded to an unsupported kernel, data may not be accessible from the
virtual machine's PVSCSI disks. Run vmware-config-tools.pl with the kernel-version
parameter to regain access.
◆
Booting a Linux guest from a disk attached to a PVSCSI adapter is not supported.
◆
Booting a Microsoft Windows guest from a disk attached to a PVSCSI adapter is not
supported in ESXi prior to ESXi 4.0 Update 1.
Configuring disks to use VMware Paravirtual SCSI (PVSCSI) adapters (1010398), available
in the VMware Knowledge Base, provides detailed information.
Note: Hot-adding a PVSCSI adapter to a virtual machine is not supported. Configure
PVSCSI on the storage controller when the virtual machine is created.
N-Port ID Virtualization for RDM LUNs
N-Port ID Virtualization (NPIV) within the FC protocol enables multiple virtual N-Port IDs to
share a single physical N-Port. This feature provides the ability to define multiple virtual
initiators through a single physical initiator. It enables SAN tools that provide Quality of
Service (QoS) at the storage-system level to guarantee service levels for virtual machine
applications. It also allows a storage administrator to provision a storage directory to the
virtual adapter on the VM bypassing the hypervisor storage stack.
NPIV does have some restrictions. Adhere to the following guidelines to enable NPIV
support:
◆
VMware NPIV support is limited to RDM volumes.
◆
Both the host HBAs and the FC switch must support NPIV.
◆
Enable NPIV on each virtual machine.
◆
Each virtual machine must have at least one RDM volume assigned to it.
◆
Mask LUNs to both the ESXi host and the virtual machine where NPIV is enabled.
Within VMware ESXi, NPIV is enabled for each virtual machine so that physical HBAs on
the ESXi host assign virtual initiators to each virtual machine. As a result, a virtual
machine has virtual initiators (WWNs) available for each HBA. These initiators can log in to
the storage like any other host to provision block devices directly to the virtual machine
through Unisphere.
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Figure 62 shows how to enable NPIV for a virtual machine. To enable the NPIV feature,
present an RDM volume through the ESXi host to the virtual machine. Virtual WWNs are
assigned to that virtual machine after NPIV is enabled.
Figure 62 Enable NPIV for a virtual machine after adding an RDM volume
The virtual WWNs must be zoned in order to create a storage group for the virtual machine
on the VNX. If the virtual WWNs are not are listed in the switch utilities, manually add them
with an alias for the virtual machine, and then zone them to the storage system ports. The
virtual machine initiator records then appear within the VNX Connectivity Status window
for registration, as shown in Figure 63. Create a separate storage group for each
NPIV-enabled virtual machine. In addition, present any LUNs assigned to the virtual
machine storage group to the ESXi storage group.
Figure 63 Manually register virtual machine (virtual WWN) initiator records
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Complete the following steps to configure NPIV:
1. Ensure that the HBA and the FC switch support NPIV.
2. Assign an RDM volume to the ESXi host, and then to the virtual machine.
3. Enable NPIV to allow the virtual machine to create virtual WWNs.
4. Manually type in the virtual WWNs in the switch interface.
5. Zone the virtual WWNs to the VNX platforms in the switch interface. Add them to the
same zone that contains the ESXi HBA and VNX storage ports.
6. Use Unisphere to manually register the initiator records for the virtual machine, and
set the virtual machine to failover mode 4 (ALUA)
7. Create a new virtual machine storage group and assign the virtual machine records to
it.
8. Add LUNs to the virtual machine:
a. Mask the LUNs to the ESXi hosts and the virtual machine storage group.
b. Assign the LUNs the same host LUN number (HLU) as the ESXi hosts.
c. Assign the LUNs to each virtual machine as RDM volumes.
Virtual machines resiliency over NFS
VNX Data Mover disruption in vSphere environments can result in application
unavailability, and guest operating system crashes.
In the event of a Data Mover disruption, the guest OS loses its connection to the NAS
datastore on the VNX file system. Virtual machine I/O requests to virtual disks in the NAS
datastore experience Disk SCSI Timeout errors in the OS system event viewer.
Use the following best practices on the guest OS to keep the application and virtual
machines available during VNX Data Mover outage events and avoid downtime:
◆
Configure the environment with at least one standby Data Mover to avoid a guest OS
crash and application unavailability.
◆
Configure the Data Mover and ESX host to take advantage of DNS round-robin for NFS
path fault tolerance.
◆
Install the VMware tools for the guest OS.
◆
Set the disk timeout value to at least 60 seconds in the guest OS.
◆
For a Windows OS, modify the
HKEY_LOCAL_MACHINE/System/ControlSet/Services/DISK and set the
TimeoutValue to 120. The following command performs the same task and can be
used for automation on multiple virtual machines:
reg.exe add \\%1\HKLM\SYSTEM\CurrentControlSet\Services\Disk
/V TimeoutValue /t /REG_DWORD /d 120 /f
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Monitoring and managing storage
vSphere makes it possible to proactively monitor storage utilization through vCenter
datastore alarms. Datastore monitoring is particularly useful when using thin provisioned
VNX storage. It helps prevent out-of-space conditions when thin virtual disks are
provisioned on thin LUNs.
This section explains how to proactively monitor the storage utilization of vSphere
datastores within vCenter and use the Storage Viewer feature of VSI. It also explains how
to monitor the utilization of the underlying VNX file system LUNs when they are thinly
provisioned through Unisphere.
Note: As described in “EMC VSI for VMware vSphere” on page 25, Storage Viewer exposes
the datastore and VNX storage details. Use the information presented in “VSI: Storage
Viewer” on page 27 to configure VNX file system and LUN monitoring through Unisphere.
Monitoring datastores using vCenter
Use vSphere Client to display the current utilization information for NFS and VMFS
datastores. Configure vCenter to trigger datastore alarms that occur in response to events,
conditions, and state changes of datastores within the inventory. Create and modify the
alarms from a vSphere Client connected to a vCenter Server. Datastore alarms, as shown
in Figure 64, can be set for a single datastore, a host, or an entire datacenter.
Complete the following steps to create a datastore alarm:
1. From vSphere Client, select the datastore to monitor.
2. Right-click the datastore and then select Add Alarm.
3. Click General and then type the required properties:
a. Type the alarm name and description.
b. In the Monitor list box, select Datastore.
c. Select Monitor for specific conditions or state, for example thin LUN utilization.
d. Add a trigger to warn at 80 percent capacity, and to alert at 90 percent capacity.
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e. Add an action to generate email notifications when the condition occurs.
Figure 64 Data Alarm Settings-Actions window
When VNX Thin Provisioning is in use, you should correlate the storage information
presented in vCenter with the storage utilization from the storage array. Storage Viewer
feature does this from within the vSphere Client.
To accomplish this task, complete the following steps:
1. From vSphere Client, select an ESXi host.
2. Click the EMC VSI tab.
This tab lists three subviews of EMC storage information in the Features Navigation
panel: Datastores, LUNs, and Targets.
3. Click Datastores.
The Storage Viewer\Datastores information is displayed.
4. Select a datastore from the list of datastores.
The Storage Details window lists the storage devices or the NFS export that back the
selected datastore.
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Note: The highlighted VP column in the Storage Details pane displays Yes if thin
provisioning is enabled on the LUN. Figure 65 shows the information that appears in
Storage Viewer for a VMFS datastore provisioned on a VNX LUN.
Figure 65 Storage Viewer\Datastores window-VMFS datastore
Thin provisioning enables physical storage to be over-provisioned. The expectation is that
not all users or applications require their full storage allotment at the same time. They can
share the pool and conserve storage resources. However, it is possible that applications
may grow rapidly and request storage from a storage pool with insufficient capacity. This
section describes a procedure to avoid this condition with VNX LUNs.
Unisphere monitors storage pool utilization and displays the current space allocations.
Administrators can add alerts to objects to be monitored with the Event Monitor, and send
alerts via email, page, or SNMP traps. Unisphere provides the following:
◆
Usable pool capacity is the total physical capacity available to all LUNs in the storage
pool.
◆
Allocated capacity is the total physical capacity currently assigned to all thin LUNs.
◆
Subscribed capacity is the total host-reported capacity supported by the pool.
When LUN allocations begin to approach the capacity of the pool, the administrator
receives alerts. Two non-dismissible pool alerts are provided:
◆
A warning event is triggered when the pool exceeds a user-defined value between 1
and 84 percent.
◆
A critical alert is triggered when the pool reaches 85 percent.
Both alerts trigger a user-defined, associated secondary notification.
Complete the following steps to configure a user-defined alert on the storage pool:
1. Access EMC Unisphere.
2. In the Systems list box, select the VNX platform.
3. Select Storage > Storage Configuration > Storage Pools for Blocks.
The Pools window appears.
4. Select the storage pool for which to set the alert. Click Properties to display the
Storage Pool Properties window.
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5. Click the Advanced tab.
6. In the Percent Full Threshold list box, type or select a value as the threshold at which
to generate an alert.
In Figure 66, the Percent Full Threshold value in the Advanced tab of the Storage Pool
Properties dialog box is set to 70 percent. Alerts are sent when the utilization of the
storage pool reaches 70 percent.
Figure 66 Adjustable percent full threshold for the storage pool
Adding drives to the storage pool non-disruptively increases the available usable pool
capacity.
Note: Allocated capacity is only reclaimed by the pool when LUNs are deleted. Removing
files or freeing space within a virtual machine disk does not free space within the pool.
Monitor thinly provisioned file storage on VNX with EMC Unisphere.
Administrators must monitor the space utilization in over-provisioned storage pools and
thinly provisioned file systems to ensure that they do not become full and deny write
access. Configure and customize notifications based on the file system, storage pool
usage, and time-to-fill predictions. Notifications are particularly important when
over-provisioned resources exist in the environment.
Use VNX file system notifications to proactively monitor VNX file systems used for NFS
datastores and generate SMTP (email) or SNMP (network management) alerts when an
event occurs.
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Multiple notification settings can be applied to the same resource to provide information
about a trend or a worsening condition.
Configuring VNX file-system storage usage notification
Complete the following steps to configure a notification based on the percentage used of
the maximum capacity:
1. Access EMC Unisphere to select the VNX platform.
2. Select System > Monitoring and Alerts > Notifications for Files.
3. Click Storage Usage, and then click Create.
The Create Storage Usage Notification window is displayed.appears as shown in
Figure 67.
Figure 67 Create Storage Usage Notification window
4. Specify the storage information:
a. In the Storage Type field, select File System.
b. In the Storage Resource list box, select the name of the file system.
Note: Notifications can be added for all file systems.
c. Select Maximum Size.
Note: Maximum Size is the autoextension maximum size and is valid only for file
systems with autoextend enabled.
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d. In the Condition field, type the percentage of storage (percent used) and then
select % Used from the list box.
Note: Select Notify Only If Over-Provisioned to trigger the notification only if the file
system is over provisioned. If this is not selected, a notification is sent every time
the condition is met.
e. Type the email or SNMP address, which consists of an IP address or hostname and
community name. Use commas between multiple email addresses or trap
addresses.
f. Click OK.
The configured notification appears in the Storage Usage window as shown in
Figure 68.
Figure 68 User-defined storage usage notifications
Configure VNX file-system storage projection notification
Complete the following steps to configure notifications for the projected file-system-full
time:
1. Access EMC Unisphere and select the VNX platform.
2. Select System > Monitoring and Alerts > Notifications for Files.
3. Click Storage Usage, and then click Create.
4. Specify the storage information:
a. In the Storage Type field, select File System.
b. In the Storage Resource list box, select the name of the file system.
Note: Notifications can be added for all file systems.
c. In the Warn Before field, type the number of days to send the warning notification
before the file system is projected to be full.
Note: Select Notify Only If Over-Provisioned to trigger this notification only if the
file system is over provisioned.
d. Specify optional email or SNMP addresses.
e. Click OK.
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The configured notification is displayed in the Storage Projection window as shown
in Figure 69.
Figure 69 User-defined storage projection notifications
Note: Unisphere has no comparable capability for block storage. VSI provides a useful way
to monitor space utilization for block storage.
VNX storage system resource monitoring
Coincident with the release of vSphere 5.1, EMC has provided new options for monitoring
the resource utilization of the VNX storage system.
EMC VNX Monitoring and Reporting
The EMC VNX Monitoring and Reporting product provides an extended set of tools and
system views to help understand storage utilization and workload patterns. It presents
resource information in a several formats, including color-coded graphical views to quickly
identify and isolate storage resource constraints.
The product collects data from one or more VNX systems and stores it in a database to be
used for problem diagnosis, trend analysis, and capacity planning.
VNX Monitoring and Reporting includes a web interface to view VNX storage system
inventory, performance information, capacity planning metrics, and health information.
Figure 70 shows an example of a capacity planning report that illustrates the storage
system utilization over the past month.
Figure 70 VNX Monitoring and Reporting: Capacity Planning Report
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Figure 71 illustrates a performance report for the same system. The output is generated by
the Top IOPS report. This report lists the top 5 consumers. The N represents a user
selectable value that defines how many entries you want to display on each page. Top N
IOPS for the storage pools lists the top 6 storage pools and RAID groups in the system
along with the current values for throughput and bandwidth.
Figure 71 VNX Monitoring and Reporting - Performance report
This product simplifies the collection and presentation of performance information. Data
is presented in easily understandable graphs with views of global and isolated resources
so that the user easily identifies a potential resource imbalance or utilization problem.
The product provides key performance indicators that are normally obtained through
Unisphere Analyzer. Users of Analyzer will be familiar with the metrics and use VNX
Monitoring and Reporting to complement Analyzer through automated collection and
reporting.
VNX Analytics for vCenter Operations Manager
The second monitoring feature is an extension to VMware vCenter Operations Manager.
vCenter Operations (vC Ops) provides a comprehensive view into the resources within the
vSphere environment. It offers comprehensive monitoring of host, virtual machine,
Network, and storage utilization metrics. It applies patented analytics to establish normal
conditions and infer a health score for each resource. Figure 72 illustrates the The vCenter
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Operations Manager dashboard interface that quickly identifies the state of the
environment. Each component is assigned a numerical value and color (green, yellow, red)
to indicate its health state.
Figure 72 vCenter Operations Manager Dashboard
EMC has developed an adapter for vCenter Operations Manager connector to allow vC Ops
to collect and store information about the VNX storage system. vC Ops polls the VNX for
utilization metrics at five minute intervals and stores the results in the vCenter Operations
Manager database for up to 30 days.
In addition to monitoring the array status, the VNX connector provides metrics for the
resource types as shown in Table 9.
Table 9 VNX Connector metrics
Resource types for block
Resource types for file
Storage processor
Data Mover
FAST Cache
NFS export
Storage Pool
File System
RAID group
File pool
LUN
Disk volume (dVol)
Disks
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vCenter Operations Array Block and File performance interfaces, illustrated in Figure 73,
enables administrators to view performance metrics in real time. Administrators use the
information to identify potential resource imbalance or over-utilization conditions and
take measure to adjust or balance resources on the storage system or vSphere
environment.
Figure 73 vCenter Operations Manager: VNX Storage Analytics
As cloud computing evolves, understanding how resources are consumed across the
environment and how one resource impacts another become increasingly important.
Products such as EMC Monitoring and Reporting and VNX Analytics Suite provide the
information to assist you in quickly identifying the root cause of a performance problem
and relate that to applications and services in the environment. Storage efficiency
Thin provisioning and compression are practices that administrators use to store data
more efficiently. This section describes how to use these technologies in an environment
with vSphere and VNX.
Thinly provisioned storage
Thin provisioning is a storage efficiency technology that exists within VMware vSphere and
EMC VNX. With thin provisioning, the VNX presents the host with a storage device that is
not fully allocated. VNX performs an initial allocation with a portion of the device capacity.
Additional space is consumed on an as-needed basis by the user, applications, or
operating system. When using vSphere with VNX, the following thin provisioning
combinations exist:
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◆
On ESXi, through ESXi Thin Provisioning
◆
On VNX file systems, through thinly provisioned VNX file systems
◆
On VNX block LUNs, through VNX thin LUNs.
Monitor the storage utilization to prevent an accelerated out-of-space condition when thin
provisioning is in use. For thin virtual disks on thin LUNs, the storage pool is the
authoritative resource for storage capacity. Monitor the pool to avoid an out-of-space
condition.
Virtual machine disk allocation
vSphere has renamed the virtual disk identifiers between versions. This document uses
the current naming conventions. Table 10 provides the reference to describe virtual disks
in vSphere 4.
Table 10 Command line descriptions for vSphere 5.5,vSphere 5, and vSphere 4
vSphere 5.5
vSphere 5
vSphere 4
Command line
Thick lazy zeroed
Flat
Thick
ZeroedThick
Thick eager zeroed
Thick
Fault Tolerant
EagerZeroedThick
Thin
Thin
Thin
Thin
VMware offers the following options to provision a virtual disk: thin, flat (ZeroedThick),
and thick (EagerZeroedThick). Table 11 provides a description of each option, along with a
summary of their impacts on VNX storage pools. Any supported VNX storage device (thin,
Thick, VNX OE, or NFS) can provision any of the options.
Table 11
Allocation mechanism
(virtual disk format)
Virtual machine disk allocation policies
VMware kernel behavior
Impact on VNX pool
Thin provisioned (NFS
default)
Does not reserve any space on the VMware file
system on creation of the virtual disk. The space
is allocated and zeroed on demand.
Minimal initial VNX
pool allocation.
Allocation is
demand- based
Thick Lazy Zeroed/Flat
(VMFS default)
All space is reserved at creation, but is not
initialized with zeros. The allocated space is
wiped clean of any previous contents on the
physical media. All blocks defined by the block
size of the VMFS datastore are initialized on the
first write.
Reserves.vmdk size
within the LUN or
pool. Allocation
occurs when blocks
are zeroed by the
virtual machine.
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Table 11
Allocation mechanism
(virtual disk format)
Virtual machine disk allocation policies (continued)
VMware kernel behavior
Impact on VNX pool
Thick Eager Zeroed
Allocates all the space and initializes every block
with zeros. This allocation mechanism performs
a write to every block of the virtual disk.
Full allocation of
space in the VNX
storage pool. No
thin benefit.
RDM
Creates a virtual disk as a mapping file that
contains the pointers to the blocks of the SCSI
disk it maps. The SCSI INQ information of the
physical media is virtualized. This format is
commonly known as the “Virtual compatibility
mode of raw disk mapping.”
Allocation depends
on the type of file
system or
application.
pRDM
Similar to the RDM format except that the SCSI
INQ information of the physical media is not
virtualized. This format is commonly known as
the “Pass-through raw disk mapping.”
Allocation depends
on the type of file
system or
application.
Thinly provisioned block-based storage
Thinly provisioned storage for VNX is available only when using storage pools, and more
specifically when using thin LUNs. Thick LUNs reserve space and classic LUNs are fully
allocated on RAID groups. Thin LUNs preserve storage pool space by deferring block
allocations until the ESXi host or a guest virtual machine allocates new blocks within the
VMFS data store (or virtual disk). This architecture provides the ability to oversubscribe
the storage pool when using thin LUNs.
In this section, the discussion of block-based thin provisioning focuses exclusively on VNX
thin LUNs for VMFS or RDM volumes.
VMFS datastores are thin-friendly, which means that a VMware file system on a thin LUN
uses a minimal number of extents from the storage pool. A VMFS datastore reuses
previously allocated blocks, and thereby benefits from thinly provisioned LUNs. For RDM
volumes, the file system of the guest OS dictates whether the RDM volume is thin-friendly.
Virtual machine disk provisioning options with block storage
The default virtual VMFS virtual disk format is thick lazy zeroed (also referred to as Flat in
some releases). Lazy zeroed disks do not initialize or claim all the space during creation.
The virtual disk space is reserved within the VMFS datastore, but blocks are not zeroed
until they are allocated by the virtual machine.
Figure 74 illustrates the creation of a 500 GB virtual disk with 100 GB of data written to the
disk. These actions result in 500 GB of file space reserved from the VMFS file system and
100 GB of space allocated in the VNX storage pool. This disk format provides faster
allocation time and space conservation within thin LUNs. However, blocks allocated within
this virtual disk format cannot be returned to the pool after allocation.
Note: Quick Format helps to preserve storage space. If a Windows file system is formatted
with NTFS, each block is zeroed, which performs a full allocation at the storage pool level.
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Use the Quick Format option for NTFS volumes to preserve space.
Figure 74 Thick or ZeroedThick virtual disk allocation
Use thin virtual disks to preserve space within the VMFS datastore. They consume only the
space that is required or consumed by the guest OS or application. When configured on
thick LUNs or datastores, thin virtual disks limit consumption of the LUN space. When thin
virtual disks are configured on a thin LUN, this benefit is extended to the storage pool.
Figure 75 illustrates the same 500 GB virtual disk within a VMFS volume.
Figure 75 Thin virtual disk allocation
This time the virtual disk is created using the thin-provisioned format. With this option,
the VMFS uses only 100 GB within the file system and 100 GB within the VNX storage pool.
Additional space is allocated when the virtual machine needs it. The allocation unit is the
equivalent of the block size for the VMFS datastore. Instead of allocating at the 4k, 8k, or
32k block size used by the guest operating system of the virtual machine, ESXi performs
an allocation of 1 MB, which is the default block size for VMFS-5. This allocation improves
locality, which is beneficial for a thin-on-thin configuration.
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The default format for virtual machine disks is Flat (ZeroedThick). Figure 76 shows that you
should select one of the other options if you need a thick or thin disk.
Figure 76 Virtual machine disk creation wizard
Selecting the thick lazy zeroed option for virtual disks on VMFS volumes can provide space
savings. If the guest performs a file system format on the virtual disk, it will consume the
equivalent amount of VMFS space.
In ESXi, configure a virtual machine disk as flat or thin. With the thin virtual disk format,
the VMFS datastore is aware of the space the virtual machine consumes. When using thin
format, monitor the VMFS datastore's free capacity to avoid an out-of-space condition
within the datastore. vSphere provides a simple alert for this condition.
In addition, with ESXi, the ZeroedThick or thin format remains intact on the destination
datastore after the use of vCenter features such as Cloning, Storage vMotion, Cold
Migration, and Deploying a Template. The consumed capacity of the source virtual disk is
preserved on the destination virtual disk, and is not fully allocated.
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Because the virtual machine is not thin-aware, tan out-of-space condition can occur when
the storage pool that backs a thin LUN reaches its full capacity. If the thin LUN cannot
accommodate a new write request from the virtual machine due to an out-of-space error,
ESXi pauses the virtual machine I/O and generates an alert in the vSphere Client, shown in
Figure 77.
Figure 77 Virtual machine out-of-space error message
The virtual machine does not generate any I/O while in this state.
Do not select Retry, as this results in repeated failures until additional capacity is added
for the thin LUN by expanding a storage pool or removing space from another virtual
machine or LUN consumer. Do one of the following:
◆
Select Cancel to power off the virtual machine.
◆
Select Retry to resume the virtual machine after adding or reclaiming additional
storage capacity.
◆
Restart any applications that time out while waiting for storage capacity to become
available.
◆
Select Cancel to power off the virtual machine.
File-based thinly provisioned storage
File-based thin provisioning with VNX is available by using VNX Thin Provisioning for file
systems. Both Unified Storage Management and Unisphere can set up Thin Provisioning
on a file system.
Thin Provisioning and Automatic File System Extension are enabled by default.
Automatic File System Extension on the file system is controlled by the High Water Mark
(HWM) value in the Advanced window for provisioning NFS datastores on new NFS
exports, as shown in Figure 78. This value (percentage) determines when to extend the file
system. By default, VSI sets the HWM to 90 percent. This means that the file system
extends itself when 90 percent of the capacity is consumed. The NFS datastore is created
using the Unified Storage Management feature of VSI and presented to the VMware ESXi
host with the file system maximum capacity.
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Configuring VMware vSphere on VNX Storage
The ESXi host is unaware of the currently allocated capacity in the file system, but you can
view the currently allocated capacity of the file system in the Storage Viewer feature of VSI.
Figure 78 File system High Water Mark in the Unified Storage Management feature of VSI
Additional virtual machines can be created on the datastore even when the aggregated
capacity of all their virtual disks exceeds the datastore size. Therefore, it is important to
monitor the utilization of the VNX file system to identify and proactively address upcoming
storage shortages.
Note: “Monitoring and managing storage” on page 99 provides further details on how to
monitor the storage utilization with VMware vSphere and EMC VNX.
The thin provisioned virtual disk characteristics are preserved when a virtual machine is
cloned or migrated to another datastore or when its virtual disk is extended.
VNX-based block and file system operations that affect a datastore are transparent to the
virtual machine disks stored in them. Virtual-provisioning characteristics of the virtual
disk are preserved during all the operations listed above.
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VMware vSphere virtual disks based on NFS storage are always thin provisioned. Figure 79
shows the virtual disk provisioning policy settings for NFS.
Figure 79 Provisioning policy for an NFS virtual machine virtual disk
LUN compression
VNX LUN compression offers capacity savings for data types with lower performance
requirements. LUNs presented to the VMware ESXi host are compressed or decompressed
as needed. Figure 80 shows that compression is a LUN attribute that you can enable or
disable for each individual LUN. When enabled, data on the disk is compressed in the
background. If the source is a RAID group LUN or thick pool LUN, it undergoes an online
migration to a thin LUN when compression is enabled. Additional data written by the host
is initially stored uncompressed, and system-defined thresholds are used to automatically
trigger asynchronous compression of any new data.
Hosts decompress data in memory to read it, but the data remains compressed on disk.
These operations are largely transparent to the end user, and the system automatically
processes new data in the background when compression is in use.
Figure 80 LUN compression property configuration
The inline read and write operations of compressed data affect the performance of
individual I/O threads. Do not compress in the following cases:
◆
I/O-intensive or response-time-sensitive applications
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◆
Active database or messaging systems
Compression is successfully applied to more static data sets, such as archives (virtual
machine templates), nonproduction clones of databases, and messaging system
volumes, that run on virtual machines.
If compression is disabled on a compressed LUN, the entire LUN is processed in the
background. When the decompression process completes, the LUN remains a thin LUN
and remains in the same pool. Capacity allocation of the thin LUN after decompression
depends on the original pre-compression LUN type.
File deduplication and compression
The VNX file deduplication and compression feature provides data reduction for files,
which improves file-storage efficiency. Deduplication eliminates redundant files in a file
system with minimal impact to the end user. The use of these technologies results in lower
cost-per-megabyte and improved TCO of the VNX system.
VNX file deduplication and compression provide data-reduction cost-savings capabilities
in these categories:
◆
Efficient deployment and cloning of virtual machines that are stored on VNX file
systems over NFS
◆
Efficient storage of file-based business data stored on NFS or CIFS network shares
accessed by virtual machines
Deployment of virtual machines stored on NFS datastores
VNX file deduplication and compression targets active virtual disk files. This feature is
available for VMware vSphere virtual machines that are deployed on VNX based NFS
datastores.
Virtual machine compression with VNX file deduplication and compression
With this feature, the VMware administrator compresses a virtual machine disk at the VNX
level to reduce the file system storage consumption by up to 50 percent. Some CPU
overhead is associated with the compression process, but VNX includes several
optimization techniques to minimize this performance impact.
Virtual machine cloning with VNX file deduplication and compression
VNX file deduplication and compression provides the ability to perform efficient,
array-level cloning of virtual machines. Two cloning alternatives are available:
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◆
Full clone—This operation creates a full virtual machine clone that is comparable to a
native VMware vSphere clone operation. A full VNX virtual machine clone operation is
performed on the storage system instead of the ESXi host to save the ESXi CPU cycles
required to perform the native cloning operation. The result is an efficient virtual
machine clone operation that is up to two or three times faster than a native vSphere
virtual machine clone operation.
◆
Fast clone—This operation clones only the blocks that are changed between the
replica and the source virtual machine. This is very similar to a VNX LUN snapshot
operation, except that the operation is done at the file level instead of at the
LUN-level. A fast clone resides in the same file system as the source virtual machine.
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The source files satisfy unchanged block reads, and the fast clone files deliver the
updated blocks. Fast Clone creation is an almost instantaneous operation because no
data needs to be copied from the source virtual machine to the target device.
All of the compression and cloning operations available in VNX file deduplication and
compression are virtual machine-based rather than file-system-based. This provides the
administrator with the flexibility to use VNX file deduplication and compression with
VMware vSphere to further increase VNX storage efficiency.
The EMC VSI for VMware vSphere: Unified Storage Management Product Guide provides
further information on how to efficiently compress and clone virtual machines with Unified
Storage Management and VNX file deduplication and compression.
NFS and CIFS network shares
This section disucsses efficient storage of file-based business data stored on NFS/CIFS
network shares that are mounted or mapped by virtual machines.
VNX file deduplication and compression eliminates redundant files to provide a high
degree of storage efficiency with minimal impact on the end user experience. This feature
also compresses the remaining data.
VNX file deduplication and compression automatically targets files that are the best
candidates for deduplication and subsequent compression in terms of the file-access
frequency and file size. In combination with a tiered storage architecture, VNX file
deduplication and compression can also run on the secondary tier to reduce the size of
the archived dataset.
With VMware vSphere, VNX file deduplication and compression run on file systems that
are mounted or mapped by virtual machines that use NFS or CIFS. This is most suitable for
business data such as home directories and network-based shared folders. Similarly, use
VNX file deduplication and compression to reduce the space consumption of archived
virtual machines to eliminate redundant data and improve the storage efficiency of the file
systems.
VNX storage options
VNX provides a wide range of configuration options to meet the needs of any vSphere
environment. VNX is flexible enough to support basic configurations for general
environments and advanced capabilities for specific configurations required in some
environments. This section provides an overview of the different storage components and
configuration options.
VNX storage options
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VNX supported disk types
Table 12 illustrates the current drive types offered for the VNX platform and includes
general recommendations for suggested use. The drives within the system are organized
into storage pools and RAID groups. Solid state drives provide an additional option as an
extended SP cache when FAST Cache is configured on the system.
Table 12 Disk types supported by VNX
Type of drive
Available size Benefit
Suggested Use
Notes
Flash
• 100 GB
• 200 GB
• 400 GB
• Extreme
performance
• Lowest
Latency
Virtual machine
applications with low
response time
requirements
EFDs are not
recommended
for small-block
sequential I/O,
such as log files
Serial-Attached
SCSI (SAS)
•
•
•
•
•
300 GB
600 GB
900 GB
10k rpm
15k rpm
• Cost effective
• High
performance
• Large-capacity,
high-performance
VMware
environments
• Most tier 1 and 2
business
applications, such
as SQL and
Exchange
NL-SAS
•
•
•
•
•
1 TB
2 TB
3 TB
4 TB
7200 rpm
Performance and
reliability
equivalent to
SATA drives
• High-capacity
storage
• Archived data,
backups, virtual
machine template,
and ISO images
area
• Good solution for
tier 2/3
applications with
low throughput and
medium
response-time
requirements, such
as infrastructure
services DNS, AD,
and similar
applications
Disk grouping
VNX provides two types of disk grouping: RAID groups and storage pools. Both options
organize physical disks into logical groups, however, they support different LUN types with
different functional capabilities.
The primary differences between storage pools and RAID groups are:
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◆
RAID groups are limited to 16 disks. Larger disk configurations are possible using
metaLUNs.
◆
Pools can be created with higher disk counts for simplified storage management.
◆
Pools support thin LUNs (TLUs).
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◆
When configured for FAST VP, pools can use a combination of any disk types.
◆
Pools support LUN compression and deduplication.
◆
Storage pools are segmented into 256 MB slices. Pool LUNs are created using
multiple slices within the pool.
Table 13 lists the capabilities of RAID groups and storage pools.
Table 13 Pool capabilities
Pool type
LUN type
Allocation
Maximum
no. of disks
RAID
group
FLARE
LUN
Full
18






Storage
pool
Thin
(TLU)
No
allocation
121-996
determined
by platform






Thick
(DLU)
No
allocation
space is
reserved
Expansion
Compression Deduplication Unmap Shrink
Auto
tiering
Note: MetaLUNs provide the ability to extend RAID groups. Enabling LUN compression
converts the existing LUN to a thin pool LUN. FLARE LUNs can be shrunk when running
Windows 2008 with Solutions Enabler.
Although pools are introduced to provide simplicity and optimization, VNX preserves RAID
groups for internal storage devices used by data protection technologies and
environments or applications with stringent resource requirements.
RAID groups
RAID groups offer the traditional approach to storage management that predates storage
pools. RAID groups support up to 16 disks and RAID group LUNs, which reserve and
allocate all disk blocks at creation time.
RAID configuration options
VNX provides a range of RAID protection algorithms to address the performance and
reliability requirements of VMware environments. All block and file devices use VNX RAID
protection. Table 14 lists the RAID protection options.
Table 14
VNX RAID options
Algorithm
Description
RAID group
Pools
Considerations
RAID 0
Striped RAID.

No data protection
RAID 1
Data is striped
across all spindles.

Uses 1 minor disk for
each data disk
RAID 1/0
Data is mirrored and
striped across all
spindles.


uses 1 minor disk for
each data disk.
Consumes more disk
space than
distributed parity.
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Table 14
VNX RAID options
Algorithm
Description
RAID group
Pools
Considerations
RAID 3
Data is striped, with
a dedicated parity
disk.

RAID 5
Data is striped with
distributed parity
among all disks.


Parity RAID provides
the most efficient use
of disk space to
satisfy the
requirements of the
applications.
RAID 6
Data is striped, with
distributed double
parity among all
disks.


Additional parity
computation results
in additional write
latency.
Note: Current configurations for NL-SAS devices suggest the use of RAID 6, limiting their
use with mixed pools.
Choose the storage and RAID algorithm based on the throughput and data protection
requirements of the applications or virtual machines. The most attractive RAID
configuration options for VMFS volumes are RAID 1/0, and RAID 5. Parity RAID provides
the most efficient use of disk space to satisfy the requirements of the applications. In
tests conducted in EMC labs, RAID 5 often provides the broadest coverage of storage
needs for virtual machines. An understanding of the application and storage requirements
in the computing environment will help identify the appropriate RAID configuration.
Storage pools
Storage pools offer more flexible configuration options in terms of the number of disks,
space allocation, and LUN types. Pools provide advanced features such as cost-effective
thin provisioning and self-adjusting tiered storage options. Pools can be created to
support single or multitiered storage configurations created from any supported drive
type.
Pool LUNs support the following features:
◆
Thick or thin provisioned LUNs
◆
Expansion without metaLUNs
◆
LUNs that can be shrunk
◆
Block Compression (with compression enabler)
◆
Block Deduplication
◆
Auto-tiered (with FAST enabler installed)
◆
Dead space reclamation
Pool storage results in more fluid space utilization within each pool. Free space within the
pool is dynamic and fluctuates with the storage requirements of the virtual machines and
applications. FAST VP simplifies LUN configuration, allowing the pool to support different
service levels and workloads with multiple tiers of storage.
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Storage pool features
FAST VP
Fully Automated Storage Tiering for Virtual Pools (FAST VP) is configured using a
combination of two or more of the disk types listed in Table 14. FAST VP identifies the
drive type by performance tier. Tier names are:
◆
Extreme Performance (Solid State Disks)
◆
Performance (SAS)
◆
Capacity (NL-SAS)
Flash provides the highest performance with the lowest capacity requirement. NL-SAS
provides the best capacity and lowest cost, and SAS disks provide a performance tier that
is a blend of both.
Note: Rotational speed is not differentiated within a FAST VP tier. Therefore, disks with
different rotational speeds such as 10k and 15k RPM SAS drives are assigned to the same
pool tier. EMC does not recommend this configuration.
LUNs created within the pool are distributed across one or more storage tiers. FAST VP
operates at a subLUN level using a 256 MB segment called a slice. When a LUN is created,
slices are distributed across the available tiers within the pool. The policy assigned to the
pool and existing tier utilization determines the slice distribution for the LUN.
FAST VP pools perform slice relocation to align the most frequently used storage with the
highest tier, and the less frequently used storage with the lowest tier. Slice rebalancing
occurs automatically at scheduled periods of the day or is manually completed by an
administrator.
VNX OE for Block version 5.32 and later performs slice rebalancing within a tier when a
pool is expanded or when the software that monitors the slices identifies hot spots on
private LUNs within the storage pool. The slice rebalance at EMC labs showed minimal
performance impact during pool expansion and improved performance benefits when the
slice rebalancing is completed.
FAST VP is beneficial because it adjusts to the changing data access patterns in the
environment as block usage patterns change within the vSphere environment.
Unisphere provides configuration guidance for all pool creation tasks. FAST VP pools are
bound in multiples of five disks for RAID 5 pools, eight disks for RAID 1/0 pools, and eight
disks for RAID 6 pools.
Pool expansion should adhere to these configuration rules, and grow in similar
increments to the existing configuration to avoid parity overhead and unbalanced LUN
distribution. For example, if the existing pool configuration is made up of 20 disks, the
pool should be expanded with 20 disks for even extent distribution of LUNs within the
pool.
Figure 81 shows the Unisphere tiering window. The window indicates that 47 GB of data is
identified for migration to the Performance tier and 28 GB will be moved to the Extreme
Performance tier. In this example, the pool-tiering policy is set to Manual. The
administrator must manually initiate the relocation for the migration to occur.
VNX storage options
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Block relocation with FAST VP is not generally performed in real time. Depending on the
workload, it is best to schedule the relocation to occur during periods of lower use.
Figure 81 VNX FAST VP reporting and management interface
FAST Cache
FAST Cache is an optimization technology that greatly improves the performance of
applications such as databases within VMware environments. FAST Cache uses Solid
State disks to store the most frequently used data within the system. FAST Cache operates
at a 64 KB extent size. If a block within an extent is accessed multiple times within a
system-defined interval, the extent is promoted to the flash disks, where subsequent
access requests result in a significant performance improvement.
As access to data blocks within cached extents becomes less frequent or block priorities
change, they are de-staged to HDD and replaced with the higher priority extents. FAST
Cache operates in real time, which results in more frequent migration of extents to match
the access requirements of the virtual machines.
Note: FAST Cache is best suited for data reuse. Applications with heavy reuse or hot
regions achieve more benefit than those that perform sequential reads or writes. If your
application is more sequential in nature, configure the SSDs as part of a FAST VP pool to
achieve better performance.
Advanced snapshots
VNX OE for Block version 5.32 supports a new LUN snapshot capability called advanced
snapshots. Advanced snapshots are used to create instantaneous snapshot images of
storage pool LUNs.
With advanced snapshots, you can:
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◆
Create up to 256 copies of any source LUN.
◆
Create a snapshot of an existing snapshot.
◆
Delete snapshots at any time, in any order.
◆
Create consistency groups for application-consistent images of multiLUN storage
devices.
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Advanced snapshots do not perform copy-on-write operations, which means write
operations require little overhead. They perform allocate-on-writes operations to write
updated data to a new area within the storage pool.
VNX Snapshots do not require additional setup or reserved LUNs. Snapshots use available
space within the storage pool.
VNX LUNs
Table 13 shows the LUN types supported by each storage pool. The following comparison
describes the LUN options available in VNX.
Thick LUNs
The default LUN created in a storage pool is called a thick LUN. These LUNs consist of 1 GB
slices which are distributed across storage groups within the pool.
Thick LUNs require three 1 GB slices for metadata. Based on the version of VNX OE for
Block running on the system, the remaining slices are either reserved or allocated.
In releases of VNX OE for Block prior to 5.32, the remaining slices are reserved within the
pool and additional slice allocation is performed when the virtual machine or host
requires additional space within the LUN.
In VNX 5.32, Thick LUN space is allocated at creation time. This change improves the
locality of blocks within the LUN.
A pool LUN uses a number of disks based on the size of the pool, available slices, and the
LUN size. Pools perform initial slice placement based on available space. Depending on
how full a pool is, a LUN may not be striped across all disks that make up the pool. VNX OE
for Block version 5.32 monitors slice activity and rebalances them to adjust the
distribution of slices within the pool.
Thin LUNs
Thin LUNs (TLUs) are created within storage pools when the Thin enabler is installed. Thin
LUNs require three 1 GB slices for metadata. Since the goal of thin LUNs is to preserve
space, block allocation is deferred until a virtual machine or host requires additional
space and new space is allocated at a more granular eight KB size.
To limit the amount of space consumed by thin LUNs, their space is not reserved within
the storage pool. This capability allows the storage pool to be oversubscribed with many
TLUs whose configuration size may exceed the pool capacity. Thin LUNs should be used
with “thin friendly” storage and applications. Thin LUNs work best when they are not filled
on a regular basis or their capacity is dynamic—filling for a period and then releasing the
space back to the pool. If the potential exists for the LUNs you are configuring to all fill at
the same time, they might not be a good candidate for TLUs. Oversubscribed storage
pools should be monitored to detect when pool space is getting low. “Monitoring and
managing storage” on page 99 provides more details on how to monitor VNX storage.
VNX storage options
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Thin LUNs versus thick LUNs
Table 15 illustrates the major differences between thick and thin LUNs.
Table 15 Thin LUNs versus Thick LUNs
Thin LUNS
Thick LUNs
Allocate space at a more granular
level using 8 KB increments to
conserve storage space
Reserve and allocate (blocks in VNX
5.32) all of the required slices
Provide no reservation which
means that all of the TLUs in the
pool are sharing the free space of
that pool
Favor performance
Favor space reuse, particularly with
the Dead space reclamation
functionality included in ESXi 5.0
U1 and later
Classic LUNs
Classic LUNs (RAID group LUNs) are the traditional devices created from fixed disk groups.
All disk blocks associated with a classic LUN are allocated in a contiguous manner when
the LUN is created. Classic LUNs have a fixed limit of 16 drives with no thin LUN option.
VNX metaLUNs
A metaLUN is an aggregate LUN created by striping or concatenating multiple LUNs from
different RAID groups. They allow VNX to present a single RAID group device that spans
more than 16 disks to provide more resources for capacity or distribute the workload
among more spindles when using RAID groups.
Pool LUN versus RAID group LUN performance
Each LUN type uses a different allocation approach.
RAID LUNs allocate all blocks when the LUN is created, providing a higher probability that
the LUNs will have good spatial locality or skew. This layout usually results in better LUN
response times. RAID LUNs can use metaLUNs to create aggregate devices with linear
scalability. LUNs created from a RAID group offer the most predictable LUN performance.
With VNX OE for Block version 5.32 and later, thick LUNs also perform all block allocation
when created. This provides locality and performance similar to RAID group LUNs.
Thick LUNs created prior to VNX OE for Block 5.32 do not perform an initial allocation and
can have spatial locality and response times that are marginally different than the RAID
group LUNs. Depending on the configuration, thick LUNs have up to 10 percent
performance overhead when compared to RAID-group LUNs.
Thin LUNs preserve space on the storage system by deferring block allocation until the
space is required. This can impact the response time for thin LUNs, and could result in a
difference of 20 percent or more when compared with a RAID-group LUN.
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VNX File volumes
VNX OE for File version 7.1 uses the same LUNs and LUN types described in the
introduction section to create NFS file systems for vSphere environments. VNX LUNs are
imported into the file environment as disk volumes (dvols). VNX OE for File volume
manager is used to create aggregate, stripe, and slice dvols for file systems that are
presented to ESXi as NFS datastores.
Most LUN properties and features described in this document also apply to file system
storage for NFS datastores.
VNX provides two approaches to volume creation: Automated Volume Management (AVM)
and Manual Volume Management (MVM). AVM provides templates to automate the
creation of volumes and VNX file systems. It simplifies the creation by applying best
practice algorithms to the existing storage resources.
MVM enables the storage administrator to select the components to be used to create the
volume, providing additional flexibility and precise configuration of an NFS volume.
VNX volume management allows administrators to:
◆
Create customized volumes for file system storage.
◆
Group, combine, and slice volumes to meet specific configuration needs.
◆
Manage VNX volumes, file systems, and LUNs though a single interface.
AVM generated volumes meet the requirements for most VMware deployments.
MVM is best suited to file system configurations with specialized application
requirements. MVM provides an added measure of control for precise selection and layout
of the storage configuration. The MVM interface allows the creation of file systems with
different characteristics.
Unisphere exposes a set of configuration wizards that allow the administrator to reserve
LUNs exclusively for the file environment. The Disk Provisioning Wizard illustrated in
Figure 82 allows the storage administrator to define pools of storage for file provisioning.
Figure 82 Disk Provisioning Wizard
VNX storage options
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CHAPTER 2
Cloning Virtual Machines
This chapter presents the following topics:
◆
◆
◆
Introduction .......................................................................................................... 128
Using EMC VNX cloning technologies .................................................................... 128
Summary .............................................................................................................. 138
Cloning Virtual Machines
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Introduction
Virtualized environments benefit from the ability to quickly create replicas of existing
virtual machines. The two types of vCenter initiated virtual machine replicas are:
◆
Full virtual machine replicas or clones that are block-for-block copies of a virtual
machine and its virtual disks
◆
Snapshot replicas that are typically thin journal file images, or block/file system
pointer-based images of the files that constitute the virtual machine and its virtual
disks
VMware provides the following native replication capabilities to clone virtual machines
through the Clone Virtual Machine wizard in vCenter, and the VMware vCenter Converter
Standalone utility:
◆
Clone Virtual Machine wizard—Enables users to create a clone of an existing virtual
machine and store it on any supported datastore accessible to the ESXi host. The
wizard also provides the option to clone the virtual disks using a different allocation
policy, such as thin, to preserve the amount of space within a datastore.
◆
vCenter Converter—Enables users to convert any Windows system to a virtual machine
on an ESXi host. It also provides the ability to clone an existing virtual machine, and
optionally, to resize existing virtual disks. This tool is invaluable for resizing operating
system disks with minimal downtime and administrative effort.
In most cases the native snapshot and replication wizards within vCenter provide the best
virtual machine replication option. They offer integrated vCenter functionality to automate
and register the virtual machine replicas.
EMC provides alternative replication options to create and register virtual machine
replicas on NFS datastores, and create datastore replicas on VNX storage devices.
VNX provides the following features for virtual machine clones:
◆
VNX SnapView™ for block storage when using the FC, iSCSI, or FCoE protocols.
◆
VNX SnapSure™ for file systems when using the NFS protocol.
◆
VMware VAAI technology for block storage to accelerate native virtual machine
cloning.
◆
VAAI plug-in for NFS to perform space-efficient FAST virtual machine clones on NFS
datastores.
◆
VSI Unified Storage Management for individual virtual machine cloning.
Using EMC VNX cloning technologies
This section explains how to use the EMC VNX software technologies to clone virtual
machines. The VNX platform-based technologies produce exact copies of the storage
devices that back the vSphere datastores and RDM virtual disks.
To produce reliable storage system clones, take the following precautions prior to creating
a clone of a VNX storage device:
◆
128
Shut down or quiesce applications running on the virtual machines to commit all data
from memory to the virtual disk.
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◆
Use the Windows System Preparation tool, Sysprep, or a comparable tool to place the
virtual machine in a deployable state.
◆
Assign a unique virtual machine hostname and network address to avoid identity
conflicts with other virtual machines.
◆
For Windows virtual machines, run Sysprep within the guest operating system to
automatically generate a new security identifier and network address upon system
boot.
Replicating virtual machines with VNX SnapView
VNX SnapView technology creates copies of VMFS datastores or RDM LUNs that support
virtual machines.
SnapView enables users to create LUN-level copies for testing, backup, and recovery
operations. SnapView includes three flexible options:
◆
Pointer-based, space-saving snapshots—SnapView snapshots use pointer-based
technology to create point-in-time images of existing LUNs. SnapView maintains the
snapshot image contents by copying source LUN blocks before updates are applied to
the source LUN. A single source LUN can have up to eight snapshots to capture the
contents of the LUN over a period of time.
◆
VNX advanced snapshots—VNX OE for Block version 5.32 supports advanced
snapshots to create up to 256 snapshots of pool-based LUNs. An advanced snapshot
is a pointer-based copy of the source LUN, however, modified blocks are not written to
the snapshot. Advanced snapshots maintain the pointers to the original blocks and
new blocks are allocated to accommodate block changes to the source LUN. Advanced
snapshots write updates to the LUN within the storage pool and do not require a
separate reserved LUN pool.
◆
Full-volume clones—SnapView clones are full-image copies of a source LUN that can
be used for almost any business purpose. SnapView tracks the block changes of the
device. This resynchronizes a clone device with the source with changes from a prior
synchronized state. A LUN can have up to eight simultaneous target clones.
Replicating virtual machines on VMFS datastores with SnapView clones
VNX LUNs are formatted as VMFS datastores or surfaced to virtual machines as RDM
volumes. SnapView clones can be used to replicate the VMFS datastore by creating an
identical block-for-block replica of a LUN used by ESXi.
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SnapView cloning is managed through Unisphere or Navisphere® CLI. Figure 83
illustrates the interface used to create and present a cloned LUN to an ESXi host.
Figure 83 Unisphere clone LUN management
Complete the following steps to create and present a cloned LUN:
1. Use Unisphere Host Virtualization interface or the EMC VSI Storage Viewer feature to
identify:
a. The VNX LUN that supports the VMFS datastore
b. The virtual machines contained within the datastore
2. Define a clone group for each VNX LUN to be cloned.
3. Add clone target LUNs to each clone group.
Adding target devices automatically starts the SnapView clone synchronization
process.
4. Fracture the clone volumes from the source volumes after they have synchronized.
This step preserves the current LUN state and sets the LUNs to a read/write state so
the LUNs can be accessed by an ESXi host.
You can create multiple VNX clones of the same source LUN. To make use of the clone,
fracture it from the source LUN and present it to a storage group as shown in Figure 84.
Any ESXi host that is part of the storage group is presented with a consistent read/write
copy of the source volume at the time it was fractured.
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Note: To perform this task with the Navisphere CLI utility (naviseccli), specify the
-consistent switch to perform a consistent fracture.
Figure 84 Performing a consistent clone fracture operation
Replicating virtual machines on VMFS datastores with SnapView Snapshot
To create and present SnapView snapshots, complete the following steps:
1. Use the Unisphere Host Virtualization interface to identify the source devices to snap.
2. Use Unisphere to create a SnapView snapshot of the source devices.
A Snapshot establishes the necessary storage resources for the snapshot LUN.
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3. Use either Unisphere or Navisphere CLI, as shown in Figure 85, to start a SnapView
session on the source device. This step initiates the copy-on-write activity.
Figure 85 Creating a SnapView session to create a copy of a VMware file system
ESXi volume signatures
The ESXi VMkernel assigns a unique signature to all VMFS-formatted disks. The signature
is based on the device ID of the LUN. It also includes user-assigned properties such as the
datastore/volume name. A replicated VNX storage device is an exact block-for-block copy
that includes the unique signature and volume details.
The VMkernel performs a SCSI device inquiry on all devices accessible to the host to
discover the properties of the device and determine if there is an existing device
signature. If vSphere detects that the device contains a signature of an existing device, it
prevents it from being mounted and presents the option to use the LUN by assigning a
new signature to the device. When presenting the replica to a host that is not part of the
same cluster, keep the existing signature to mount the device.
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After a rescan, do one of the following:
◆
Keep the existing signature—Presents the copy of the data with the same label name
and signature as the source device. ESXi does not surface a replica when a signature
conflict exists. Assign a new signature to activate the replica on the same host as the
source LUN.
◆
Assign a new signature—Assigns a new signature to the VMFS volume replica. The
new signature is computed using the UID and LUN number of the replica LUN. The
default format of the new label assigned to the datastore is snap-snap_ID-old_label,
where snap_ID is an integer and old_label is the label of the original datastore.
To resignature a SnapView clone or snapshot LUN:
1. Rescan storage on the ESXi host to perform device discovery and update the SCSI
device list.
2. Select the host from the Inventory area.
3. Select Configuration, and then click Storage in the Hardware area.
4. Click Add Storage.
5. Select the Disk/LUN storage type and click Next.
6. Select the LUN, from the list of LUNs, that displays a datastore name in the VMFS Label
column, and then click Next.
The Select VMFS Mount Options dialog box appears.
Note: The name presented in the VMFS Label column indicates that the LUN is a copy
of an existing vStorage VMFS datastore.
7. Select Keep the existing signature or Assign a new signature, as shown in Figure 86,
and then click Next.
Figure 86 Device signature assignment
8. Review the datastore configuration information, and then click Finish.
9. Browse the new datastore to locate the virtual machine's configuration (VMX) file and
import it to the vCenter inventory.
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Replicating virtual machines with SnapView clones of RDM LUNs
Replicating an RDM volume requires a copy of the source virtual machine configuration
files to facilitate access to the replicated RDM volumes. SnapView technology creates a
logical, point-in-time copy of the RDM volume. In turn, the copy is presented to a virtual
machine.
An RDM volume has a one-to-one relationship with a virtual machine or virtual machine
cluster.
To replicate virtual machines with SnapView clones of RDM LUNs, complete the following
steps:
1. Create a SnapView clone or snapshot of the RDM LUN.
2. Within vCenter, identify the ESXi host where the clone image will be created.
3. Create a folder within an existing datastore to hold the copy of the virtual machine
configuration files.
4. Use the Datastore Browser in the vSphere Client, as shown in Figure 87, to copy the
configuration files of the target virtual machine to the directory created in step 3.
Figure 87 Selecting virtual machine configuration files in the datastore browser
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5. Identify the copy of the virtual machine configuration file (VMX) and use it to add the
new virtual machine to the inventory of the ESXi host, as shown in Figure 88.
Figure 88 Adding the new virtual machine to the ESXi host inventory
6. Edit the following virtual machine settings:
a. Remove the existing Hard Disk entry referring to the source RDM.
b. Add a new hard disk as type RDM, and specify the cloned RDM device.
7. Power on the cloned virtual machine from the vSphere Client.
Cloning virtual machines on VNX NFS datastores with VNX SnapSure
The VNX SnapSure feature creates a logical, point-in-time image (checkpoint) of an NFS
file system that supports an NFS datastore that contains virtual disks and virtual machine
configuration files. The ESXi host requires the file system to be in read/write mode in order
to boot the virtual machine.
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A writeable Checkpoint File System is created in Unisphere as shown in Figure 89.
Figure 89 Creating a writeable NAS datastore checkpoint
Execute the following command in the CLI to create writeable Checkpoint File Systems:
# fs_ckpt <NAS_file_system_checkpoint> -Create -readonly n
To start the virtual machine, the VMkernel requires read/write and root access to the
Checkpoint File System. “Creating an NFS datastore using VSI” on page 51 provides more
details. Export the checkpoint file system to the ESXi hosts to provide them with root-level
access.
To import multiple virtual machines on a Checkpoint File System, complete the following
steps in the vCenter UI:
1. Select an ESXi host with access to the Checkpoint File System.
2. Select Configuration and click Add Storage.
3. Add the writeable Checkpoint File System to the ESXi host as an NFS datastore.
4. Browse for the new datastore and add the VMX files of the virtual machines to the
vCenter inventory.
Cloning virtual machines with native vCenter cloning and VAAI
This section explains how vCenter virtual machine cloning works with VAAI-enabled VNX
block storage. The VAAI operations preserve ESXi resources that are consumed if the host
performs the clone. The resources used are proportional to the amount of data to be
copied.
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VAAI allows VMware vSphere version 4.1 and later to take advantage of efficient disk-array
storage functions as an alternative to ESXi host-based functions. These vStorage APIs
enable close integration between vSphere and storage hardware to:
◆
Provide better quality of service to applications running on virtual machines.
◆
Improve availability through rapid provisioning.
◆
Increase virtual machine scalability.
vStorage API supports VMFS datastores, RDM volumes, and NFS systems with the VNX
platform. The minimum VNX release versions for VAAI offload are VNX OE for Block 5.31
and VNX OE for File 7.0.45. The Full Copy feature of the VAAI suite offloads virtual machine
cloning operations to the storage system.
Note: VAAI support is provided with VNX storage systems running VNX OE for Block version
5.31 and later.
ESXi hosts issue the XCOPY command to the array supporting the source and destination
devices. The array performs internal data copy operations to create virtual disk replicas.
The host issues copy operations to the array which performs the data movement. SCSI
status messages are exchanged between the storage system for flow control and copy
completion. The array copy offload results in a significant reduction of host I/O traffic and
CPU utilization. The full copy feature is supported only when the source and destination
LUNs belong to the same VNX platform.
Administrators find the full copy feature useful to:
◆
Create multiple copies of a virtual machine within or across LUNs on the same storage
system.
◆
Storage vMotion virtual machines from one VMFS datastore to another when the LUNs
reside on the same storage system.
◆
Deploy virtual machines from a template using VNX LUNs.
Cloning individual virtual machines on NFS datastores
vSphere 5.0 introduced VAAI support for NFS copy operations when cloning virtual
machines on NFS datastores.
ESXi hosts configured with the EMC NAS software package offload copy operations to the
VNX Data Mover. All replication or cloning is performed within the storage environment to
minimize consumption of host and network resources.
The EMC NAS software package is required for this functionality. It is available to EMC
customers and partners as a VMware Installation Bundle (VIB) from EMC Online Support.
VAAI offload for NFS reduces the amount of ESXi host resources required to perform the
clone tasks. It also reduces network resource utilization on ESXi and VNX systems.
Install the EMC NAS VIB package from the ESXi console, or as an autodeploy image in
vSphere. To verify that EMC NAS VIB is installed, use the vSphere Client or run the
following command:
esxcli software vib list |grep EMCNas
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Figure 90 illustrates the datastore properties of a VNX VAAI-enabled NFS datastore that
has been configured with the NFS plug-in.
Note: The datastore list denotes that Hardware Acceleration is supported.
Figure 90 Cloned NFS datastore in vSphere
NFS VAAI clones do not always result in a faster execution time than host-based clone
operations. This is particularly true when tests are performed in isolation with no other
load on the environment. The benefit of the offload operations is in the resource
utilization and cumulative benefit when these operations are performed under contention
for host resources, and not when the host is idle.
VNX also provides individual virtual machine cloning capabilities when the virtual
machine resides on an NFS datastore. The VSI Unified Storage Management feature
performs cloning operations directly within the storage system using a separate
management approach from the VAAI cloning operations.
The utilities in Unified Storage Management include full clones and fast clones.
◆
Full clone—Full clone operations are performed across file systems within the Data
Mover. By removing the ESXi host from the process, the virtual machine clone
operation can complete two to three times faster than a native vSphere virtual
machine clone operation.
◆
Fast clone—Fast clone operations are performed within a single file system. Fast
clones are near-instantaneous operations executed at the Data Mover level with no
external data movement. Unlike full clones, fast clone images only contain changes to
the cloned virtual machines and reference the source virtual machine files for
unchanged data. They are stored in the same folder as the source virtual machine.
The EMC VSI for VMware vSphere: Unified Storage Management Product Guide, available
on EMC Online Support, provides more information about the Unified Storage
Management feature.
Summary
The VNX platform-based technologies provide an alternative to conventional
VMware-based cloning. VNX-based technologies create virtual machine clones at the
storage layer in a single operation. Offloading these tasks to the storage systems provides
faster operations with reduced vSphere CPU, memory, and network resource
consumption.
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VNX-based technologies provide options for administrators to:
◆
Clone a single or small number of virtual machines and maintain the granularity of
individual virtual machines.
◆
Clone a large number or all of the virtual machines with no granularity of individual
virtual machines on a datastore or LUN.
Options for the VNX-based technologies are listed in Table 16.
Table 16 VNX-based technologies for virtual machine cloning
Storage type
Individual virtual machine
granularity for a small number of
virtual machines
No granularity for a large
number of virtual machines
Block storage
(VMFS datastores or
RDM)
VMware native cloning with VAAI
Full Copy
VNX SnapView
Network-attached
storage
(NFS datastores)
VNX File Data Deduplication using
the VSI Unified Storage
Management feature
VNX SnapSure
Summary
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CHAPTER 3
Backup and Recovery Options
This chapter presents the following topics:
◆
◆
◆
◆
◆
◆
◆
◆
◆
◆
◆
◆
◆
Introduction ..........................................................................................................
Virtual machine data consistency ..........................................................................
VNX native backup and recovery options ...............................................................
Snapshot backup and recovery of a VMFS datastore..............................................
Backup and recovery of RDM volumes ...................................................................
AppSync ...............................................................................................................
Replication Manager .............................................................................................
Backup and recovery of a VMFS with VNX Advanced Snaps....................................
vStorage APIs for Data Protection ..........................................................................
Backup and recovery using VMware Data Protection..............................................
Backup and recovery using Avamar .......................................................................
Backup and recovery using NetWorker...................................................................
Summary ..............................................................................................................
Backup and Recovery Options
142
142
143
145
148
148
154
157
164
165
183
189
193
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Backup and Recovery Options
Introduction
The combination of EMC data protection and VMware vSphere technologies offers several
backup and recovery options for virtual environments.
This chapter discusses two types of data protection available at the storage layer: logical
backup and physical backup.
◆
A logical backup (snapshot) establishes a point-in-time image of the VNX file system
or LUN. Logical backups are created rapidly and require very little storage space,
allowing them to be created frequently. Restoring from a logical backup can also be
accomplished quickly, dramatically reducing the mean time to recover. Logical
backups protect against events such as file system corruption and accidental deletion
of files.
◆
A physical backup creates a full copy of the file system or LUN. The full backup
provides a complete and independent copy of the source data. It can be managed and
stored on devices that are separate from the source device.
A logical backup cannot replace a physical backup. Although full backup and recovery may
require more time, a physical backup provides a higher level of protection because it
guards against hardware failures.
When considering backup solutions, determine a recovery point objective (RPO) and a
recovery time objective (RTO) to ensure that an appropriate method is used to meet
service-level requirements and minimize downtime.
Virtual machine data consistency
When RDM is used in VMware environments, all virtual disks reside on a datastore or a
LUN. In a basic configuration, all of the virtual disks are stored on the same datastore and
you can use native VNX features to provide crash consistency of a virtual machine by
creating a replica of the LUN or NFS file system that supports the datastore.
Application vendors, especially database vendors, recommend distributing applications
across multiple virtual disks and datastores to achieve better performance. In this type of
configuration, all datastores that support the application must be managed as a single
entity. VNX consistency groups can be used with VMware snapshots to provide crash
consistency of block storage devices in these cases.
A VMware snapshot is a log-based protection mechanism in which changes made to a
virtual disk are applied to a journal file. The hypervisor suspends all Virtual Machine I/O
prior to the creation of a virtual machine snapshot. The snapshot captures the entire
virtual machine state, including configuration settings, virtual disk contents, and the
contents of the virtual machine memory.
When I/O resumes, the virtual machine writes are applied to the snapshot virtual disk, or
delta file, leaving the source disk unchanged. Because updates are not applied to the
original virtual disk, the virtual machine can be restored to the pre-snapshot state by
discarding the delta files. If the snapshot is deleted, the delta file and virtual disk files are
merged to create a single file image of the virtual disk.
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EMC backup technologies use VMware snapshots to ensure that the virtual machines are
in a consistent state prior to creation of an NFS SnapSure checkpoint or SnapView LUN
snapshot. When a virtual machine spans datastores, the backup set consists of EMC
snapshots of all the datastores containing the virtual machine’s disks.
A backup must contain all virtual machine files in order to preserve the system state when
the snapshot is created. Ensure that the backup set includes all datastores where the
virtual machine disks and files might reside, taking into account features like Storage DRS
that might have relocated a virtual machine from its initial datastore placement.
Performing a backup
Note: EMC Replication Manager is used to automate these steps and provide application
integration and application consistency. “Replication Manager” on page 154 provides
more information.
1. Initiate a VMware snapshot.
2. Set the flags to quiesce the file systems. Optionally, capture the memory state.
3. Create a VNX NFS file system checkpoint or LUN snapshot of the datastore device that
contains the virtual machine disks to be backed up.
Note: EMC Storage Viewer and Unisphere Virtualization views assist with the
identification of the VNX storage devices backing each datastore. “VSI: Storage
Viewer” on page 27 provides more details.
4. Delete the VMware snapshot.
Restoring a virtual machine from a snapshot
1. Power off the virtual machine.
2. Initiate the NFS/LUN restores for all datastores containing virtual disks that belong to
the virtual machine.
3. Update the virtual machine status within the vSphere UI by restarting the management
agents on ESXi host console.
Detailed information is available in Restarting the Management agents on an ESXi or
ESX host (1003490), available in the VMware Knowledge Base.
Wait 30 seconds for the console to refresh.
4. Open the VMware Snapshot Manager and revert to the snapshot taken in the backup
operation. Delete the snapshot.
5. Power on the virtual machine.
VNX native backup and recovery options
VNX offers native utilities to create replicas of file systems and LUNs. While these utilities
can be used to protect ESXi Datatstores in a vSphere environment, EMC provides
comprehensive solutions like AppSync and Replication Manager with application-level
integration for enterprise-level backup and recovery.
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EMC Replication Manager enables creation of VMFS and NFS datastore replicas, and
provides point-and-click backup and recovery of virtual machine-level images. It provides
selective file restore in VNX OE for Block versions 5.31 and later.
File system logical backup and restore using VNX SnapSure
Use VNX SnapSure to create near-linear logical backups of individual NFS datastores
mounted on ESXi hosts. Unisphere provides an interface to create one-time file system
checkpoints and to define a checkpoint schedule to automate the creation of new file
system checkpoints on VNX.
Note: SnapSure Checkpoint File Systems are stored in a hidden folder at the root of the
source file system. A change in the Data Mover configuration is required to make the folder
visible and perform selective copies from the vCenter Datastore Browser. To make the
hidden directory visible, set the value of the Data Mover parameter showChildFSRoot to 1,
as shown in Figure 91.
Figure 91 Viewing ChildFsRoot parameter properties in Unisphere
Recovering a virtual machine from an NFS checkpoint
Virtual machine files within a datastore are backed up and recovered as a single
operation. To recover an individual virtual machine from an NFS checkpoint, perform the
following steps:
1. Power off the virtual machine.
2. Browse to the Checkpoint File System to locate the folder that contains the virtual
machine.
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3. Use the Datastore Browser to select and copy the files from the Checkpoint File System
to the existing datastore location on the ESXi host.
4. Power on the virtual machine.
Physical backup and restore using VNX File Replicator
Use VNX File Replicator to create a physical backup of NFS datastores. Replicator performs
local or remote replication through the /nas/bin/nas_replicate command or through the
Unisphere UI. Replicator creates an independent file system allowing for selective virtual
machine recovery or complete file system restoration through Unisphere.
Selective virtual machine recovery
Selective virtual machine recovery is performed through a host copy. After the file system
copy is complete, stop the replication to transition the target file system to a stand-alone
read/write copy. Mount the target file system to any ESXi host and copy the virtual
machine files or folders through the datastore browser.
Best practices:
◆
When using file system restore, ensure that all virtual machines within the file system
are recovered to the same point in time.
◆
Virtual machines with different management or service level requirements should be
placed in separate file systems.
Note: If virtual machine snapshots exist before the creation of a backup, vCenter Snapshot
Manager might not report them correctly when a virtual machine is restored. In this case,
remove the virtual machine from the vCenter Inventory, import it again, and verify that the
virtual machine is recognized correctly. Do not delete the virtual disks while removing the
virtual machine from Inventory!
File system recovery
To recover an entire file system, establish a replication session from the target file system
to the production file system with the nas_replicate command.
Snapshot backup and recovery of a VMFS datastore
EMC SnapView for VNX provides the functionality to protect VMFS datastores using either
logical replicas (snapshots), or full volume copies (clones) of VNX LUNs. This storage
system functionality can be accessed using Unisphere, Unisphere Snapshot Configuration
Wizard, or the admsnap utility.
For simplified configuration, automation, and monitoring of replication jobs in enterprise
environments, you can control LUN protection using Replication Manager or AppSync
Manager. The utilities described in this section offer a manual approach to create or
restore a replica of a VNX LUN.
When a snapshot is activated, SnapView tracks all data blocks of the LUN. As the LUN is
modified, original data blocks are copied to a separate device in the reserve LUN pool.
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Similarly, a clone private LUN pool is used to maintain various states between source and
target LUNs in a clone relationship. Ensure that the reserved LUN and the clone private
LUN pools are configured before performing these operations.
SnapView operates at the LUN level, which means that VNX snapshot replicas are most
effective when the datastore is provisioned from a single LUN.
Best practices:
◆
To simplify snapshot management of VMFS datastore LUNs, create the datastore from
a single LUN.
◆
Use metaLUNs or pool LUNs for larger single LUN datastores.
◆
If multiple virtual machines share the same VMFS datastore, they are backed up and
restored together as part of the snap or restore operation. While it is possible to
perform manual restores of individual virtual machines from a snapshot LUN, it is best
to group similar virtual machines within a datastore to avoid inadvertent impact from
a restore operation.
To create a snapshot LUN using the Unisphere Snapshot Configuration Wizard, complete
the following steps:
1. In Unisphere, launch the wizard and identify the production server where the source
LUN exists.
2. Select the required VNX storage system and LUN for the SnapView session as shown
in Figure 92.
Figure 92 Snapshot Configuration Wizard
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3. Select the number of copies for each source LUN.
4. Optionally, assign the snapshot to other ESXi hosts as shown in Figure 93.
Figure 93 Snapshot Configuration Wizard (continued)
5. Type the snapshot name.
6. Select the host to which you want to add the snapshot image.
Unisphere assigns the LUN to the host's storage group.
7. Review the configuration information and click OK to create and mount the snapshots.
8. Use Unisphere to start the snapshot session and activate the snapshot for access by
another host.
9. Rescan the ESXi hosts to verify that the storage appears in the correct location.
10. If required, select Assign a new signature to automatically resignature the device.
“ESXi volume signatures” on page 132 provides more information on device
signatures.
When the snapped VMFS LUN is accessible from the ESXi host, you can copy virtual
machine files from the snapped datastore to the original VMFS datastore to recover the
virtual machine.
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Backup and recovery of RDM volumes
VNX LUNs provisioned to ESXi hosts are formatted as VMFS file systems or presented
directly to a virtual machine as RDM (raw device map) devices. RDM volumes possess
similar properties to VMFS virtual disks, while retaining the capabilities of a physical
device. Storage administrators can take full advantage of storage array-based data
protection technologies at the LUN level. EMC data protection products such as SnapView
and AppSync provide native protection of RDM devices.
To back up an RDM volume, a variety of EMC replication technologies are available to
create usable copies of the device.
For RDM volumes, snapshots or clones can be created as follows:
◆
By using the admsnap command or the Unisphere Snapshot Configuration Wizard
◆
By using Replication Manager or AppSync to integrate with Windows applications or
create stand-alone snapshots or clones of the RDM volumes
Note: Replication Manager only supports RDM volumes created in physical compatibility
mode and formatted as NTFS volumes.
AppSync
AppSync is an EMC data protection product that simplifies replication of ESXi datastores.
Appsync is integrated with EMC VNX Snapshots, EMC SnapSure, EMC RecoverPoint, and IP
replicator to create local or remote replicas of VNX datastores.
AppSync identifies all on-line virtual machines and initiates the creation of virtual
machine snapshots prior to creating local replicas. The VMware snap attempts to quiesce
all I/O to the virtual machine before the snap is created, providing a higher level of
consistency than simply snapping the datastore at the device level.
AppSync uses a proxy (physical or virtual) host to communicate with the vCenter and VNX
storage systems. It performs device enumeration within both environments and and
initiates the necessary management tasks to establish consistent copies of the datastores
and virtual machine disks. The AppSync Job Wizard simplifies the definition of the backup
task providing options to select the replica type and expiration options.
Note: AppSync version 1.5 is required for NFS datastore support.
Configuring AppSync
To configure AppSync:
1. Log into AppSync using the desktop shortcut.
2. Select Storage Infrastructure from the settings.
3. Click Add VNX Storage System.
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4. Type the IP Addresses of the SP and the administrative user credentials.
Figure 94 Adding a VNX Storage System to AppSync
5. Add a vCenter-Server:
a. Go to Protection > VMware Datacenter and click Discover Datacenter.
b. Click Add vCenter Server.
c. Type the system properties and select Run Discovery Now.
AppSync is authenticated to vCenter and lists all existing datastores.
AppSync provides Service Plans to map an application's Service Level Objectives (SLO) to
the datastore. To simplify configuration, AppSync provides templates for VMware
Datacenters, Microsoft Exchange, and Microsoft SQL.
Adding a Service Plan
To add a new Service Plan:
1. From the AppSync management interface, select Service Plans > VMware Datacenter.
2. Click Create and enter the system properties.
3. Choose the service level and provide a name.
To adjust this Service Plan to your own needs, click on its name.
4. Select a Recovery Point Objective.
For example, the service plan named “four hours” creates a new snapshot of each
datastore in the plan, every four hours.
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5. Confirm your changes and click Apply.
Figure 95 Editing Service Plan settings
Once the protection plan has been created, you can use it to protect datastores in the
environment. The following steps and illustration in Figure 96 illustrate the protection of a
datastore using the protection plan created in “Adding a Service Plan.”
Protecting the datastores
1. Click Protection > VMware Datacenter.
2. Select the datacenter to view a list of all datastores.
3. Select a VMFS Datastore on the VNX system and select Protect to assign it to the newly
created Service Plan.
4. Select the Service Plan to which you want to assign the datatore.
In this example VMFS Datastore Local is assigned.
Figure 96 Subscribing to a Service Plan
AppSync provides immediate protection. A check mark appears next to datastores that
are protected.
Figure 97 Overview of protected and unprotected datastores
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VSI AppSync Management
The AppSyncManagement feature of VSI offers protection for VMFS and NFS datastores.
Both AppSync and Replication Manager allow you to take application and virtual
machine-consistent snapshots or replications. ReplicationManager supports all of EMC's
diverse data protection capabilities, whileAppSync is tailored for VNX and EMC
RecoverPoint. Both products feature a VSI plugin.
Configuring AppSync in VSI
1. Login to a vSphere Client where VSI is installed.
2. Select AppSyncManager from the VSI Features window.
3. Click Register.
4. Enter the AppSync system credentials and click Next.
5. Enter the vCenter credentials and click Finish to complete the configuration and exit
the wizard.
Figure 98 VSI AppSync registration
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Protecting a datastore using AppSync Management
1. From the vSphere Client, clickvSphere > Datastores and Datastore Clusters.
Figure 99 Protect datastore
2. Right-click the datastore you want to protect, and then select EMC > AppSync >
Configure Protection.
Figure 100 Using VSI AppSync Feature to Configure datastore protection
3. In the AppSync wizard, perform the following steps to complete the configuration:
a. Select Create and Subscribe.
b. Select the VMFS datastore local protection plan you created.
c. In Plan Detail, type a descriptive name and click Next.
d. Click Set Schedule to define the RPO.
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e. Click Finish.
Figure 101 Subscribe Datastores to a AppSync Service Plan
f. Validate your settings and exit the wizard.
The VMFS Datastore is immediately protected.
Mounting replicas
Using VSI AppSync Manager, you can manually create copies or restore virtual machines
by presenting the replica to any ESXi Host that is configured on the VNX storage system
where the replica was created.
1. Select the datastore in the VSI AppSync Manager menu.
2. Click Mount.
All the snapshot copies for that device are listed.
3. Select a copy and click Next.
4. Select an ESXi host on which to mount the snapshot copy.
Note: to avoid a device signature conflict between the source device and the
snapshot, ensure that Resignature is selected, as shown in Figure 102.
Figure 102 Resignaturing a copy of an existing datastore
5. Complete the wizard to complete the mount task.
Restoring a virtual machine
Once the datastore is mounted it can be browsed using the datastore browser. This is a
useful approach to performing a selective virtual machine restore. You can restore a failed
virtual machine by mounting a protected copy of the datastore from either AppSync or the
VSI AppSync Manager feature.
1. Power off the target virtual machine you want to recover.
2. Delete it from the disk.
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3. Browse to the replica datastore to identify the virtual machine to restore.
4. Copy the virtual machine folder and its contents from the replica to the root of the
production datastore.
5. Locate the VMX file and register the virtual machine.
Figure 103 illustrates these steps.
Figure 103 Using vCenter to manually copy a virtual machine
6. After the virtual machine is fully recovered, unmount the snapshot copy of the
datastore using VSI AppSync Manager.
Note: Using AppSync, you can also restore the entire datastore. This is a much quicker and
more direct restore method. However, a complete restore overwrites all virtual machines
on the source datastore. There is potential for inadvertent loss, if you restore a datastore
with active virtual machines that you did not want to change.
Replication Manager
EMC Replication Manager is a software solution that integrates with EMC data protection
technologies to simplify and automate replication tasks. Replication Manager uses EMC
SnapSure or EMC SnapView to create local or remote replicas of VNX datastores.
Replication Manager works with vCenter to create VMware snapshots of all online virtual
machines before creating local replicas. Including virtual machine snapshots provides a
higher level of consistency than simply snapping the datastore. The VMware snap
attempts to quiesce all I/O to the virtual machine before the snap is created. Replication
Manager uses a physical or virtual machine to act as a proxy host to initiate all VMware
and VNX management tasks. The proxy host is configured to communicate with the
vCenter Server and the VNX storage systems. It discovers storage devices in the
virtualization and storage environments and performs the necessary management tasks
to establish consistent copies of the datastores and virtual machine disks.
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Restoring the replicas
Use the Replication Manager Job Wizard, as shown in Figure 104, to select the replica type
and expiration options. Replication Manager 5.2.2 is required for datastore support.
1. Power off the virtual machines that reside within the datastore.
2. Remove those virtual machines from the vCenter Server inventory.
Figure 104 Replication Manager Job Wizard
3. In Replication Manager, select Restore to restore the entire datastore.
4. Restore the replica.
5. When the restore is complete, import the virtual machines to the vCenter Server
inventory.
6. Revert to the VMware snapshot taken by Replication Manager to obtain an
OS-consistent replica, and delete the snapshot.
7. Configure Replication Manager to power on each virtual machine.
Replication Manager creates a rollback snapshot for every VNX file system it restores.
The name of each rollback snapshot is available in the restore details as shown in
Figure 105.
Replication Manager
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8. Verify the contents of the restored replica, and then delete the rollback snapshot.
Figure 105 Viewing Replica Properties in Replication Manager
Restoring a virtual machine
Replication Manager version 5.3 and later provides the ability to selectively restore a
virtual machine, as shown in Figure 106.
Figure 106 Restoring a virtual machine using Replication Manager
1. Select the application set that contains the replica you want to restore.
2. Identify the date and time the replica was created.
3. Right-click the replica and select Restore a Replica, and then click Next.
4. Select the virtual machine or virtual machines to restore, and then click Next.
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The Replication Manager status pane displays the progress.
5. Revert to the VMware snapshot taken by Replication Manager to obtain an
OS-consistent replica, and then delete the snapshot.
6. Use Replication Manager to unmount the replica.
7. Power on the virtual machine.
Figure 107 Viewing a read-only copy of the datastore in vSphere Client
Backup and recovery of a VMFS with VNX Advanced Snaps
EMC VNX OE for Block release 5.32 and later provides a new snapshot architecture for pool
LUNs. Using the new snapshot you can create up to 256 snapshots of the source LUN,
including snapshots of existing LUN snapshots.
Snapshots are created from individual LUNs or groups of LUNs defined in a consistency
group.
A snapshot request creates a crash-consistent version of the selected source LUNs.
A new object called a mount point provides the management object used to present the
snap image to a storage group (that is, the host). The mount point appears as a pseudo
device within the ESXi host. The device cannot be managed or accessed until an advanced
snapshot image is attached to it. Snapshot versions are attached and detached from the
mount point to change the content within the device. Advanced snapshots are read/write
enabled, which means their content can be modified while a LUN is attached to a mount
point.
The Unisphere GUI enables you to manage advanced snapshots. Additionally a command
line utility is available for in-band management when the snapshot mount point is
enabled. Figure 108 shows this option selected to allow in-band management of the
snapshots assigned to the host.
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Using Unisphere to create snapshots of Pool LUNs
1. Right-click the LUN and select Snapshot > Create Snapshot.
Use VSI or Unisphere virtualization view to identify the datastore LUN.
Figure 108 Advanced Snapshot Basic Configuration
2. If a snapshot mount point does not exist, create one and assign it to a storage group
so the ESXi host can access the snapshot image.
In the example in Figure 109, a snapshot mount point named Blade8-MP is assigned
to Blade8. You can use Unisphere to attach and detach snapshots from the mount
point.
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Select the storage group to display the Snapshot Mount Points details, as illustrated
in Figure 109.
Figure 109 Viewing Snapshot Mount Points
3. Specify the snapshot name when the snapshot and mount point are created.
Creating consistency groups with multiLUN configurations
1. In Unisphere, select Data Protection > Snapshots.
2. Open the Snapshot Mount Points Configuration Wizard as shown in Figure 110.
The host requires a snapshot mount point for each LUN in the consistency group.
a. Select the system to mount the snapshots.
b. Select the storage system containing the LUNs to be part of the consistency group.
c. Select all of the LUNs to be part of the consistency group.
d. Assign the mount points to the host.
After the mount point is created, the host considers the mount point as a logical
device. Attempting to mount the device without attaching a snapshot does not
yield useful results.
3. Click OK to finish.
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The mount points are created for the snapshots from your application LUNs.
Figure 110 Using the Snapshot Mount Point Configuration Wizard
4. To create the consistency group, click Data Protection > Snapshots > Create Group.
5. Type the group name and, optionally, the description.
This example protects multiple Oracle Database LUNs.
6. Select the LUNs that are part of this consistency group.
As soon as a snapshot job is performed, a snapshot for each LUN is created. When one
snapshot is attached to a mount point, all LUNs are attached to the mount point.
7. Click Finish.
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Figure 111 illustrates creating the consistency group.
Figure 111 Creating a snapshot consistency group
8. To create a snapshot of all LUNs in the consistency group, select the consistency
group.
9. Select a host to add the snapshot image to the host storage group.
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Figure 112 shows the process of creating a consistency group snapshot.
Figure 112 Creating a consistency group snapshot
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Figure 113 shows how to attach the snapshots to the mount points to present them to
the host.
Figure 113 Attaching a consistency group snapshot
10. Select one of the snapshots created within the consistency group. Do one of the
following to attach a snapshot:
• Right-click the LUN to display management options and select Attach.
• Click Attach in the snapshot management window.
11. Select the host to which you want to attach the snapshots.
12. Select from the following options in the wizard:
• Attach the existing snapshot
• Create an additional snapshot copy
• Preserve the existing snapshot
13. Select Create a new snapshot to make changes to the snapshot and preserve the
existing state, or attach the copy.
14. Identify the host or cluster after logging in to vCenter. Rescan the host adapter(s) to
force the host to recognize the new SCSI devices.
15. If required, select Assign a new signature to automatically resignature the device.
“ESXi volume signatures” on page 132 provides more information on device
signatures.
16. When the snapped VMFS LUN is accessible from the ESXi host, copy the virtual
machine files from the snapped datastore to the original VMFS datastore to recover
the virtual machine.
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vStorage APIs for Data Protection
VMware vStorage APIs for Data Protection (VADP) provides an interface into the vCenter
environment to create and manage virtual machine snapshots. Data protection vendors
use VADP to automate and streamline non-disruptive, fully recoverable, incremental
virtual machine backups. A key feature of VADP is Changed Block Tracking (CBT), which
allows a data protection application to identify modified content on the virtual machine
based upon a previous VMware snapshot. This reduces the amount of data that needs to
be backed up and restored while using differential backups of virtual machines.
VADP provides the following benefits:
◆
Shorter backup times for an environment
◆
Storage savings achieved by backing up only the required data blocks instead of the
full virtual machine
VADP integrates with existing backup tools and technologies to perform full and
incremental file backups of virtual machines. Figure 114 shows how VADP works.
Figure 114 VADP flow diagram
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Backup and recovery using VMware Data Protection
VMware Data Protection (VDP) is a disk-based backup and recovery solution built on the
VADP. It uses a virtual appliance and a client plug-in to manage and restore virtual
machine backups. VMware Data Protection can protect any kind of OS. It incorporates
capabilities such as block-based data deduplication to perform incremental backups after
an initial full backup to maximize storage efficiency. VNX CIFS, iSCSI, and FC storage are
used as destination storage for VDP backups. Each virtual machine backup is stored on a
target disk in a deduplicated store.
Figure 115 VMware Data Recovery
VMware Data Protection process
1. During the backup, VDP takes a snapshot of the virtual machine and mounts it directly
to the VDP virtual machine.
2. The VDP streams blocks of data to the destination storage as shown in Figure 116.
3. During this process, VDP uses the VADP CBT functionality on ESXi hosts to identify the
changed blocks and minimize the amount of data to be backed up.
4. VDP deduplicates the stream of data blocks to further eliminate redundant data prior
to writing the backup to the destination disk.
5. The deduplicated store creates a virtual full backup based on the last backup image
and applies the changes to it.
6. When all the data is written, VMware Data Protection dismounts the snapshot and
takes the virtual disk out of snapshot mode.
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VMware Data Protection supports only full and incremental backups at the virtual machine
level, and does not support backups at the file level. Both VDP and its more sophicated
version, vSphere Data Protection Advanced (VDPA), are based on EMC2 Avamar and are
co-developed with EMC.
Figure 116 vSphere Data Protection
VDP and VDPA feature comparison
Table 17 provides a feature comparison between VDP and VDPA to help you decide which
product is best suited to protect the vSphere infrastructure in your particular environment.
Table 17 VDP and VDPZ feature comparison
Feature
VDP
VDPA
Max # virtual machines
100
400
Appliances per vCenter
10
10
2 TB
8 TB
Variable length deduplication


Global deduplication


In-guest deduplication


Change Block Tracking


CBT Restore


Microsoft Exchange


Exchange Single Mailbox Restore


Microsoft SharePoint


Microsoft SQL


Flexible schedule and retention


Max backup capacity
166
Replication topologies
1:1
1:1, 1:n, n:1
Replication targets
Avamar
VDPA, Avamar,
Data Domain
Encrypt replication
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Table 17 VDP and VDPZ feature comparison
Feature
VDP
VDPA
Backup and restore of individual vmdk file


In-guest restore of files (Windows and
Linux)


Emergency restore to an ESX- host without
vCenter


Flexible storage options


Mount existing BDP datastores to another
appliance


Automated backup tests


vSphere Integration


One-step recovery


Local data protection with vSphere Data Protection
VDP is targeted at small businesses and branch or remote offices supporting up to 100
virtual machines, depending on their size.
You must deploy VDP (or VDPA) as a virtual machine in vCenter. It is then managed through
vCenter or the vSphere web client. Apart from emergency restores, all actions are
managed within vCenter.
VDP Best Practices
EMC recommends the following best practices for VDP:
◆
Validate that all virtual machines are on hardware revision 7 to allow for changed
block tracking (CBT) backups and restores.
◆
Install VMware Tools on every virtual machine to enable the benefit of File Level
Restore (FLR).
◆
Use VMware Tools for time synchronization.
◆
Use a dedicated VMFS5 datastore as a target for the virtual disks to hold your backup
data.
VDP installation prerequisites
The following prerequisites must be met before installing VDP:
◆
Validate that all ESXi-hosts are time synchronized with vCenter.
◆
Register VDP in DNS for forward and reverse lookup.
◆
Use a dedicated VMFS Datastore to store VDPS virtual disks (3 to 12 disks with
capacities from 256GB to 1.024 GB).
◆
For the appliance, identify a fixed IP address and 100 GB capacity, which can be thin
provisioned.
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◆
Plan the capacity needed to protect your virtual machines carefully as these settings
are final and cannot be changed in VDP. The only option to change it later on is to
upgrade to VDPA.
Table 18 Capacities for VDP deployments
Big Data appliance
CPU
RAM
Hard disk
0.5 TB
4
4.096 MB
3 x 256 GB
1.0 TB
4
4.096 MB
3 x 512 GB
2.0 TB
4
6.144 Mb
3 x 1024 GB
Installing VDP
1. Download the VDP or VDPA OVA file from VMware.
2. Deploy the OVA file.
Recommendations:
• Use a dedicated VMFS Datastore based on a single LUN of a dedicated Storage
Pool to store the VDP data disks. For the storage pool physical disks choose
NL-SAS.
• Format the VDP data disks with "Eager Zero Thick."
3. When the installation completes, a web url is provided with the address of the system.
Type the url into a supported web browser to configure the system. Use the credentials
root and changeme.
4. The configuration wizard guides you through the following steps:
a. Network configuration
b. Time zone
c. Password for the appliance (root)
d. Register vCenter
e. VDP license
f. Create Storage
g. Allocate devices
h. CPU & memory
5. Validate the network settings, especially Hostname and Domain.
6. In Create Storage, select the size of your VDP deployment .
Ensure that you provide the correct settings, because the settings cannot be changed
after the configuration is complete.
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7. Optionally, clear the Store with appliance checkbox, to choose a different datastore.
Figure 117 Allocation of virtual disks on one or more datastores
A dialog box appears indicating the resources needed for CPU and Memory.
Note: Changing these values can adversely affect performance.
8. Optionally, you can run a performance check.
After the check completes it takes VDP approximately 30 minutes to be ready for
production.
9. Log on to vSphere Web Client and click vSphere Data Protection in the left pane.
The Getting Started menu appears, as shown in Figure 118.
Figure 118 vSphere Getting Started menu
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vSphere Data Protection functions
The following table describes the functions available in the vSphere Data Protection tabs.
Table 19 vSphere Data Protection tabs
Tab
Function/Description
Backup
Manage backup of virtual machines: Create, clone, edit, enable, disable, and
delete a backup job.
Restore
Manage restoring of virtual machines.
Replication
Manage replication sessions with Avamar. See “Replication Manager” on
page 154 for more information.
Reports
View all protected virtual machines including status, assigned backup jobs, and
replication.
Configuration
•
•
•
•
Adjust the backup and maintenance window to your needs.
Enter license keys.
Change to VDPA (requires a license key).
Submenus:
– Log: View log files.
– Email: Receive reports from VDP.
– Settings: Conduct an integrity check of the virtual disks holding the
backup data.
Creating a backup job
1. In the vSphere navigation pane, select vSphere Data Protection.
2. Click All Actions > Create a new backup job.
The Create a new backup job wizard appears.
3. For Data Type, select the appropriate data type.
4. For Backup Targets, choose one of the following:
• Full Image—Backs up all virtual disks and virtual dependent RDMs contained in a
virtual machine.
• Individual Disks—Backs up selected virtual disks or dependent virtual RDMs. This
method is useful for adhering to SLO, RPO, and RTO definitions.
Note: The restore job is not affected because you can select virtual disks, as shown
in Figure 119. However, Individual Disks presents only the virtual disks you select
and might not contain a boot disk.
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Figure 119 Backup with selected virtual disks
5. For Schedule, configure when backups occur. This example uses the default, Daily.
Figure 120 VDP backup schedule
6. For Retention Policy, select the parameters required by the SLO of the application to
be backed up.
Figure 121 Retention policy form
7. For Job Name, type a name for the backup job and confirm your settings.
8. Optionally, select Backup Now to immediately start the backup job.
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9. In Ready to Complete, confirm your selections and click Finish.
Local Data Protection with vSphere Data Protection Advanced
You can easily upgrade VDP to vSphere Data Protection Advanced (VDPA). The Advanced
edition features the following benefits:
◆
Application-consistent protection
◆
Automated backup verification
◆
Advanced data replication features
Upgrading to vSphere Data Protection Advanced
To upgrade to VDPA, complete the following steps:
1. In the vSphere navigation pane, select vSphere Data Protection.
2. Under All Actions, select Add a VDP Advanced License.
3. In VDP Advanced License Assignment, click Settings > Add a New License Key.
4. Type the license key provided by VMware and click Decode.
5. Click OK to accept the message that appears.
6. Under Backup applicance details, select Switch to VDPA.
7. Click OK to accept the warning.
Figure 122 License Key window
8. After you have successfully upgraded to VDPA you must reconnect to the appliance.
9. Click Configuration > Settings > Edit License Assignment to assign the license key to the
ESXi hosts.
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VDPA benefits
With VDPA you can upgrade your appliance to up to 8 TB of total capacity. Table 20
provides sizing guidelines. As the capacity grows, more compute resources are needed for
the appliance.
Table 20 Resources for VDPA-Deployments
Big Data appliance
CPU
RAM
Hard disks
0.5 TB
4
4.096 MB
3 x 256 GB
1.0 TB
4
4.096 MB
3 x 512 GB
2.0 TB
4
6.144 MB
3 x 1024 GB
4.0 TB
4
8.192 MB
6 x 1024 GB
6.0 TB
4
10.240 MB
9 x 1024 GB
8.0 TB
4
12.288 MB
12 x 1024 GB
VDPA provides application-consistent backups. Click the Configuration tab to view the
agents for deployment, as shown in Figure 123.
Figure 123 In-guest agents
Configuring replication sessions
Both VDP and VDPA allow you to create replication jobs.
◆
VDP supports Avamar only.
◆
VDPA supports various replication options, including replicating to a Data Domain
system and to another VDPA instance within your data center.
Data replication is encrypted and uses TCP port 29000, exclusively.
Configure and size your target according to your requirements. Creating a replication job
takes only a few minutes.
Replicating to an Avamar datastore
1. In the vSphere navigation pane, select vSphere Data Protection.
2. Click Replication.
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3. From the menu, select Replication Job Actions > New.
The Create a new replication job wizard appears. Virtual machines with a valid backup
are displayed.
4. Select one of the following:
• All Clients
• Select clients individually
Note: To meet application SLOs that might be different for some virtual machines,
choose Select clients individually. You can choose different schedules later in the
wizard.
Figure 124 Creating a new replication job
5. For Backup Selection, select the backup types that you want to replicate, the
maximum number of backups to replicate, and the date range limits.
Figure 125 Replication backup schedule
The Destination window identifies an Avamar datastore as a replication target.
6. Type the Avamar default user, repluser, and the password.
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7. Click Verify authentication to verify the connection, and then click OK.
Figure 126 Avamar replication target
8. For Schedule, select the parameters to define when the data replication will occur.
It is best to run the replication during off-peak hours.
Figure 127 Scheduling the replication session
9. For Retention, select the expiration parameters for the retention policy.
Figure 128 Retention policy for the Avamar target
10. In Job Name, type a name for the replication job.
11. In Ready to complete, verify your settings and click Finish.
The job starts at the time you specified. Alternatively, you can start it manually.
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Recovering data with VDP
Every copy of a virtual machine created with VDP is considered a full backup. However,
after the first backup only incremental changes are applied. A restore action is always
applied to a full backup. Backing up to disk with deduplication technology provides the
following benefits:
◆
Eliminates the need to apply incremental backups after a full restore.
◆
In VMware environments, CBT is optimized for both backup and restore to significantly
improve backup and restore times.
Best practices for restoring a virtual machine:
◆
Remove all snapshots of the affected virtual machine prior to the restore action.
VMware-Knowledgebase-article 1025279 provides more information.
◆
If you want to restore to its original location, power off the corrupted machine.
◆
If you restore to another location, you can keep the source virtual machine powered
on, but the benefit of a CBT restore is not available.
Figure 129 Restore of a powered on virtual machine
You can restore a virtual machine in the following ways:
◆
Right-click the virtual machine object in the web client and select VM All VDP 5.5
Actions > Restore Rehearsal.
◆
Use the VDP Appliance-Plug-in in the Web Client
◆
Use the VDP Restore Client (for FLR only). Open a browser window and type the URL in
the following format: https://<VDP_IP_address>:8543/flr/
You can restore virtual machines, virtual machine images, or individual disks.
Restoring a virtual machine using CBT
1. Ensure that your virtual machine is powered off.
2. From the vSphere Web Client select vSphere Data Protection.
3. In Getting Started, select Restore Backup > Restore.
4. In the Restore tab, select the check box of the virtual machine to restore.
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Use Filter to narrow your search, as shown in Figure 130.
Figure 130 Restoring a virtual machine
5. Click Restore, as shown in Figure 131.
Figure 131 Restoring a backup with VDP
6. In the following window, select Backup and click Next.
7. Ensure that Restore to Original Location is selected.
8. Select Power On and Reconnect NIC, as shown in Figure 132, to have vCenter power on
the virtual machine and connect to the network after the restore completes.
Figure 132 Setting Restore Options
9. In the Ready to Complete dialog box, click Finish.
10. To monitor the restore process, select Reports > Task Console.
Restoring a virtual machine image
When restoring a virtual machine image, the machine can be powered on and connected
to the network. This procedure does not use CBT.
1. From the vSphere Web Client select vSphere Data Protection.
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2. In Getting Started, select Restore Backup > Restore.
3. In the Restore tab, select the virtual machine to restore.
Use Filter to narrow your search.
4. Click Restore.
5. In the dialog box that appears, select Backup and click Next.
6. Clear the Restore to Original Location check box.
7. For Destination, click Choose.
8. In the dialog box that appears, select an ESXi-Host, a vSphere-Cluster, or a vApp for
the restore destination, as shown in Figure 133.
Figure 133 Selecting the restore destination
9. Under Advanced Options, select a datastore.
10. Select Power On and Reconnect NIC to have vCenter power on the virtual machine and
connect to the network after the restore completes.
Figure 134 depicts the Set Restore Options for restoring a virtual machine image.
Figure 134 Set Restore Options dialog box
11. Click Next.
12. In the Ready to Complete dialog box, click Finish.
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Restoring an individual disk using CBT
1. Ensure that your virtual machine is powered off.
2. From the vSphere Web Client select vSphere Data Protection.
3. In Getting Started, select Restore Backup > Restore.
4. Double-click the virtual machine to restore.
The Backup Type changes from Image to Disk.
5. Select the check box of the individual virtual disk to restore, as shown in Figure 135.
Figure 135 Selecting an individual disk
6. Click Restore.
7. Click Next.
8. In the Set Restore Options dialog box, clear the Restore to Original Location check box.
9. For Destination, click Choose, as shown in Figure 136.
Figure 136 Setting the Restore Options for restoring an individual disk
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10. Select an ESXi-Host, a vSphere Cluster, a vApp, or a virtual machine for the restore
destination, as shown in Figure 137.
Figure 137 Selecting the restore destination
11. Click OK.
12. In the Ready to Complete dialog box, click Finish.
After recovery, the virtual disk appears as a new SCSI device in the selected virtual
machine, as shown in Figure 138.
13. To monitor the restore process, select Reports > Task Console.
Figure 138 A virtual disk after a restore
Recovering file-level data
Both VDP and VDPA support in-guest file or directory restore of hosted Windows and Linux
platforms and dependent vRDMs.
1. Log into the guest OS or a guest OS of the same make from which you want to recover
data.
2. Open a browser window and and type the URL in the following format:
https://<VDP_IP_address>:8543/flr/
3. Choose one of the following login options, as shown in Figure 139:
• Basic Login: On the same host you want to restore data to, log in as local
administrator.
• Advanced Login: On another host of the same make, log in as local administrator
and vCenter Administrator.
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Figure 139 Login options for the vSphere Data Protection Restore Client
4. In the Manage mounted backups dialog box, shown in Figure 140, select the virtual
disks from which you want to recover files.
5. Click Close.
Figure 140 Selecting individual disks from which to restore files
6. Browse to the files you want to recover, select them and click Restore selected files.
7. Choose a destination for the selected files.
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8. Click Restore to recover the selected files and/or directories, as shown in Figure 141.
Figure 141 Restoring selected files or directories
9. Click Monitor restores to monitor the restore process, as shown in Figure 142.
Figure 142 Monitor Restores menu
10. Unnmount the drives by selecting Settings > Mounted backups > Unmount all.
11. Log off.
VDP Emergency Restore
VDP runs independently of vCenter, which enables you to restore the vCenter itself.
Note: Ensure that the ESXi host is not connected to the vCenter or that the vCenter is
powered off.
1. Open a browser window and type the URL in the following format:
https://<VDP_IP_address>:8543/vdp-configure/
and log in as root.
2. Click Emergency Restore.
3. Select the virtual machine to be restored.
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4. Click Restore.
Figure 143 Performing a VDP Emergency Restore of a virtual machine
5. In the Host Credentials dialog box, type the credentials for the target ESXi host where
the virtual machine is registered.
Figure 144 Performing an emergency restore to an individual ESXi host
6. Click OK to restore the virtual machine.
Backup and recovery using Avamar
EMC Avamar® is a backup and recovery software product that provides an integrated
software solution to accelerate backups and restores of virtual machine and application
data in a vSphere environment. Avamar provides source and global data deduplication to
reduce the amount of backup data that must be copied across the network and stored on
disk. Global deduplication means that Avamar stores a single copy of each unique subfile
variable-length data segment for all protected physical and virtual servers in the
environment.
After an initial virtual machine backup, Avamar creates full restore backups of virtual
machines that require only a fraction of the space and time used to create the original.
Avamar integration with vCenter and VMware vStorage APIs enables it to use the CBT
feature of vSphere to identify data blocks of interest for the backup job. Avamar applies
deduplication based on the global view of the stored data, and only copies globally
unique blocks to the Avamar Storage Node or Avamar Virtual Edition (AVE) server. This
greatly reduces backup times and storage consumption in the backup environment.
Avamar reduces backup times, backup capacity requirements, and ESXi host resource
utilization.
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Architectural view of the Avamar environment
Avamar Server is a core component that provides management and storage for the virtual
machine backup environment. The server provides the management, services, and file
system storage to support all backup and administrative actions. Avamar has the
following server types:
◆
Avamar Data Grid—An all-in-one server that runs Avamar software on a preconfigured,
EMC-certified hardware platform. The options include single and multinode versions
that use either internal or SAN storage.
◆
Avamar Virtual Edition for VMware (AVE)—A fully functional Avamar Server that installs
and runs as a virtual appliance within a vSphere environment.
Both physical and virtual edition products provide the same capabilities. However, AVE is
easy to deploy in a vSphere environment. It is backed by VNX block storage for high
performance, Tier 1 protection of virtual machine, application, and user data. AVE also
performs significantly better in VMware environments than the Avamar Datastore.
Figure 145 shows a sample configuration with a DRS cluster and multiple ESXi hosts with
access to VNX block LUNs. These LUNs contain the virtual machines in the environment.
The sample illustrates three types of virtual machines: production virtual machines, image
proxies, and file-level proxies.
The Production virtual machines can run any VMware-supported OS, and serve any
application role or function. In this case, the virtual machines do not require an Avamar
agent.
Figure 145 Sample Avamar environment
Backing up data using Avamar
Avamar provides the following backup options for vSphere environments:
◆
184
File Level Backup—File level backups are enabled by installing the Avamar client
within the guest OS and registering the client with an Avamar Server. This option
provides a scheduled backup of all files on the virtual machine, and allows the user to
manually backup and restore files to their desktop virtual machine. The client
capabilities are the same as when the client is installed in a physical computer
environment.
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With the Avamar client, backups complete with minimal administrative resource
requirements. Scheduled backups occur based on administrative policy. Users also
have the ability to manually initiate backups and restores at any time.
The Avamar client runs as a low priority virtual machine process to limit the impact of
the backup operation on other processes. From a vSphere standpoint, Avamar can
throttle virtual machine CPUs to limit the amount of ESXi host CPU resources
consumed during backup operations.
◆
Image Level Backups—Image Level backups allow the vSphere environment to be
backed up without installing a client on each virtual machine. They use one or more
Avamar virtual machine Image Proxy servers that have access to the shared VNX
storage environment.
The Image Proxy is provided as a downloadable OVA image. It is accessible through
the web interface of the AVE server. The Image Proxy server installs as a virtual
machine appliance within vCenter. Separate Image Proxy servers are required for
Windows and Linux virtual machine image backups.
After installation, the proxy server is configured to protect either Windows or Linux
virtual machines. Avamar integrates with vCenter, and provides a similar management
interface to import and configure virtual machine protection. Figure 146 shows a
sample proxy configuration.
Figure 146 Sample proxy configuration
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Avamar Manager can also enable CBT for virtual machines to further accelerate backup
processing. With CBT enabled, Avamar easily identifies and deduplicates the blocks that
VMware has flagged without the need to perform additional processing. This allows for
faster, more efficient backups of the virtual machine image. Figure 147 provides more
details.
Note: CBT is available with virtual machine version 7 and later. Update older virtual
machines to version 7 to backup the virtual machine with CBT enabled.
Figure 147 Avamar backup management configuration options
When a backup job starts, Avamar signals the vCenter server to create a new Snapshot
image of each VMDK specified in the backup policy. It uses VADP SCSI hot-add to mount
the snap to the image proxy. If CBT is enabled, Avamar uses it to filter the data that is
targeted for backup. After Avamar establishes a list of blocks, it applies deduplication
algorithms to determine if the segments are unique. If they are, it copies them to the AVE
server. Otherwise, it creates a new pointer that references the existing segment on disk.
The image proxy then copies those blocks to the VNX-backed virtual disks on the Avamar
Virtual Appliance.
Unique proxies are required to protect Windows and Linux environments. The
administrator can deploy additional proxies to provide scalability, and allow simultaneous
backups and recoveries. Avamar provides the ability to configure each image proxy to
protect multiple datastores from vCenter, or to load balance backups across all of them in
a round-robin fashion, to improve scalability.
Recovering data using Avamar
Avamar provides multiple recovery options. The two most common recovery requests
made to backup administrators are:
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◆
File-level recovery—Object-level recoveries account for the majority of user support
requests. File-level recovery is appropriate for:
• Deleted files
• Application recovery
• Batch process-related erasures
The Avamar client allows users to perform self-service file recovery by browsing the file
system and identifying the files they need to restore.
◆
System recovery—Complete system recovery requests are less frequent than those for
file-level recovery, but this bare-metal restore capability is vital to the enterprise.
Some common root causes for full-system recovery requests include:
• Viral infestation
• Registry corruption
• Unidentifiable, unrecoverable issues
Restoring a virtual machine image
Avamar Image Proxy
The image proxy can restore an entire image to the original virtual machine, a new virtual
machine, or a pre-existing alternate virtual machine with a configuration similar to the
original. Avamar Image Proxy can restore a virtual machine image to the same location
where it was created, a different existing virtual machine, or as a new virtual machine to a
different location in the environment. Figure 148 shows a virtual machine being restored
to its original location. In this example, the virtual machine was deleted from the disk, and
restored to the existing datastore.
Figure 148 Avamar virtual machine image restore
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Avamar file-level proxy
An Avamar file-level recovery (FLR) proxy is a virtual machine that allows one or more files
to be recovered to a virtual machine from a full image backup. This virtual machine uses
the Avamar Virtual File System (AvFS) to present a view of the virtual machine disk for
users to browse. From this view the administrator selects any file or folder to restore to the
original location, or to a new location within the same virtual machine. The Avamar
file-level proxy feature is available only for Windows virtual machines at this time.
The FLR feature uses a Windows proxy client virtual machine. The Avamar and VMware
software on the Windows proxy requires a CIFS share, which is exported by the Avamar
server.
This CIFS share provides a remote, hierarchical, file system view of the backups stored on
the Avamar server. Access the CIFS share to browse and restore the contents of the
VMware Image Backups.
When backups are selected for recovery, the FLR proxy server reads the VMDK data from
the Avamar system and creates a browse tree that is presented to the administration GUI
as shown in Figure 149.
Figure 149 Avamar browse tree
Restore requests pass from the Avamar system, through the Windows FLR proxy, and on to
the protected machine. The recovery speed of this operation is governed by the resources
of the FLR proxy to read the data and write it to the virtual machine being recovered.
Therefore, large data recoveries through the FLR proxy recovery are not advisable. In this
instance, an image-level, out-of-place recovery is more efficient.
Note: FLR requires that target virtual machines be powered on and running virtual machine
tools.
Best practices for setting up the environment
◆
188
Avoid using FLR to browse folders or directories with thousands of files or
subdirectories. A better alternative is to restore the virtual machine and use the native
OS to browse and identify the files you want to restore.
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◆
Backup of Avamar proxy clients is not required. The proxy client virtual machines are
easy to redeploy from the template if necessary.
◆
Avamar image backup is dependent on reliable DNS service and time synchronization.
Network routing and firewall settings must be correctly configured to allow access to
the network hosts that provide these services.
◆
SSL certificate must be installed across the vCenter, ESXi hosts, and Avamar proxy
virtual machine appliances. However, it is possible to turn off SSL certificate
authentication at the Avamar server.
◆
Use multiple network interfaces for HA configurations of the Avamar Datastore Node.
◆
Backups are a crash-consistent snapshot of the full virtual machine image. Use the
Avamar client for OS and application-consistent backups.
◆
An image proxy performs one backup at a time. Parallel processing is possible only
with multiple proxies in an environment.
◆
Virtual machine snapshots are required as part of the image backup process.
◆
Image backup supports the following disk types:
• Flat (version 1 and 2).
• Raw Device Mapped (RDM) in virtual mode only (version 1 and 2).
• Sparse (version 1 and 2)
Backup and recovery using NetWorker
EMC NetWorker performs agentless, full image-level backups for virtual machines running
any OS and file-level backups for virtual machines running Microsoft Windows. NetWorker
consists of the following components:
◆
Agent—NetWorker Agent architectures are particularly focused on environments that
require application consistency. For virtual machine backups that require application
integration, the agent is used to place the application and OS into a consistent state
before generating a virtual machine snapshot and performing the backup task. The
agent configuration requires additional client administration on all of the virtual
machines. If crash-consistent or operating-system-consistent images are sufficient,
VADP might be a better option.
◆
VADP—NetWorker 7.6 SP2 introduces the integration with VMware environments to
support virtual machine protection with VADP. In a NetWorker environment, VADP
creates a snapshot copy of a running virtual machine disk. NetWorker offers the ability
to create flexible backup solutions to improve backup processes, reduce backup
windows, and reduce the amount of space required to store backup images.
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Figure 150 shows the virtualization topology in an environment with NetWorker.
Figure 150 NetWorker-virtualization topology view
NetWorker backups use the VADP API to generate virtual machine snapshots on the
vCenter server. The snapshots are hot-added to a VADP proxy host for LAN-free backups. A
NetWorker initiated snapshot is identified as _VADP_BACKUP_ as shown in Figure 151.
Figure 151 Viewing a VADP snapshot
VNX storage devices for NetWorker
NetWorker offers the flexibility to use multiple storage types as targets for backup jobs.
Supported storage types include standard physical tape devices, virtual tape libraries,
and Advanced File Type Devices (AFTD) provisioned on VNX storage. An AFTD can be
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configured on the NetWorker server or Storage Node using a block LUN, or a NAS file
system. NL-SAS LUNs or VNX FAST Pool LUNs that consist of NL-SAS drives are ideal for
AFTDs.
Figure 152 NetWorker configuration settings for VADP
Guidelines and best practices for VADP with vSphere
◆
The latest version of VMware tools must be installed on all virtual machines. Without
VMware tools, the backup created by VADP will be crash-consistent.
◆
File-level backup is available only for Windows virtual machines. VADP supports
image-level backups for all other OSs.
◆
VADP does not support RDM physical compatibility mode.
◆
RDMs in virtual compatibility mode are converted to a standard virtual disk format
during backup. They are converted to VMFS virtual disks when restored.
◆
LAN mode does not allow virtual disks to exceed 1 TB each.
◆
SAN is the default backup mode. To perform LAN-based backup, change the
TRANSPORT_MODE to nbd, nbdssl, or hotadd in the config.js file.
◆
The hot-add transport mode does not support the backup of virtual disks that belong
to different datastores.
◆
VADP creates a virtual machine snapshot named _VADP-BACKUP_ before a file-level
backup. A NetWorker backup fails if a snapshot with the same name already exists.
Change the PREEXISTING_VADP_SNAPSHOT parameter in the config.js file to delete or
to modify the default behavior.
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◆
Even if a backup job fails, virtual machines remain mounted in the snapshot mode.
NetWorker Monitoring Window provides an alert if a snapshot must be manually
removed.
◆
VADP searches for the target virtual machines by IP address. The virtual machine must
be powered on the first time it is backed up, so the virtual disk information is relayed
to NetWorker through the vCenter server. This information is cached on the VADP
proxy and used for subsequent backup jobs. Change the
VM_LOOKUP_METHOD=name parameter in the config.js file to change this behavior.
Note: The backup will fail if duplicate virtual machine names exist.
◆
Beginning with the NetWorker release 7.4.1, users must add each virtual machine to
be backed up as a NetWorker client. The NetWorker client software is not required on
the virtual machine. With NetWorker release 7.4.1 or later, the VADP method to find
virtual machines is based on the virtual machine IP address (default method).
Using NetWorker to backup and restore VNX NAS file system NDMP
NetWorker provides two methods of storage integration with VNX NFS datastores. You can
use VNX file systems as
◆
Advanced File System Type Devices (AFTD)
◆
Virtual Tape Library Unit (VTLU)
1. Configure a VTLU on the VNX file system.
2. Configure NetWorker as an NDMP target to back up NFS datastores on the VNX
platform.
3. Configure NetWorker to use VNX File System Integrated Checkpoints to create NDMP
backups as follows:
a. Create a Virtual Tape Library Unit (VTLU) on VNX NAS storage.
b. Create a library in EMC NetWorker.
c. Configure NetWorker to create a bootstrap configuration, backup group, and a
backup client.
d. Run NetWorker backup.
e. Execute NetWorker Recover.
The entire datastore or individual virtual machines are available for backup or
recovery. Figure 153 shows NetWorker during the process.
Figure 153 NDMP recovery using NetWorker
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4. Set the environment variable SNAPSURE=y to use VNX file backup with integrated
checkpoints.
This feature automates checkpoint creation, management, and deletion activities by
entering the environment variable in the qualified vendor backup software.
Figure 154 shows the SNAPSURE parameter set to create a backup with an integrated
checkpoint.
Figure 154 Backup with integrated checkpoint
If the SNAPSURE parameter is set to Y, a file system checkpoint is automatically
created and mounted as read-only each time particular jobs are run and before the
start of the NDMP backup. This automated process allows production activity to
continue without interruption on the file system. The checkpoint is automatically
deleted at the end of the backup operation.
Summary
This chapter provides several backup options and examples of virtual machine protection.
Native options and tools on the VNX storage system create replicas or snapshots of the
storage devices backing the datastores. SnapSure manages point-in-time copies of NFS
datastores. LUN clones or snapshots provide similar protection for VNX block
environments.
The Virtual Data Recovery appliance is deployed and configured fairly easily and
populated with VNX block storage to support up to 100 virtual machines for each
appliance.
In larger environments, EMC Avamar scales to significantly improve global data
deduplication and reduce resource requirements for all areas of backup. EMC Avamar
Virtual Edition for VMware and Avamar Image Proxy virtual appliances are quickly installed
and configured with tight vCenter integration for vSphere environments. These products
are backed by VNX storage to provide a scalable, efficient data protection solution.
EMC NetWorker offers an image protection option for vSphere, providing tight integration
with vCenter to create and manage individual virtual machine backup and restore options.
NetWorker provides NDMP support for VNX OE for Block, as well as integration with VNX
OE for File Virtual Tape Libraries. Table 21 summarizes some of the backup technologies
and products that are used to establish image- and file-level backup approaches. The VNX
storage platform and vSphere are integrated with many data protection solutions.
Summary
193
Backup and Recovery Options
The information in this section and in the table is not a comprehensive list of qualified
products but an example of the data protection options and technologies that exist within
EMC VNX and VMware vSphere.
Table 21 Backup and recovery options
Backup/recovery
194
Storage
Image level
File level
VMFS/NFS datastore
•
•
•
•
•
• Avamar Client or File Level
Recovery
• EMC SnapSure/SnapView
/Replication Manager
RDM (physical)
Replication Manager
N/A
RDM (virtual)
• VDR
• Avamar Proxy
• NetWorker
• Avamar
• NetWorker
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Avamar Image Proxy
NDMP
VDR
EMC NetWorker
EMC SnapSure/SnapClone
CHAPTER 4
Using VMware vSphere in Data Restart Solutions
This chapter presents the following topics:
◆
◆
◆
◆
◆
◆
Introduction ..........................................................................................................
EMC remote replication technology overview.........................................................
RDM volume replication ........................................................................................
EMC Replication Manager......................................................................................
Automating site failover with SRM and VNX ...........................................................
Summary ..............................................................................................................
Using VMware vSphere in Data Restart Solutions
196
198
212
215
217
225
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Introduction
With the increased virtualization of Tier 1 applications, it is critical to have a business
continuity (BC) plan for the virtualized data center. EMC VNX systems provide native
features to define custom disaster recovery (DR) solutions. EMC replication technologies
combine with VMware vCenter Site Recovery Manager (SRM) to create end-to-end
integrated DR solutions.
This chapter focuses on the use of EMC replication technologies and SRM to create remote
DR solutions. These solutions typically include a combination of VMware virtual
infrastructure and EMC storage systems located at separate data centers. EMC
technologies perform the data replication between them.
This chapter covers:
◆
EMC replication configurations and their interaction with ESXi hosts
◆
Integration of guest operating environments with EMC technologies
◆
Use of SRM to manage and automate site-to-site DR with VNX
◆
A review of replication options, such as:
• EMC VNX Replicator
• EMC MirrorView™
• EMC RecoverPoint®
Definitions and Considerations
The following terms are used in this chapter:
◆
Dependent-write consistency—A state where data integrity is guaranteed by
dependent-write I/Os. A dependent-write I/O cannot be issued until a related
predecessor I/O is committed to the storage system.
◆
Disaster restart—Involves the implicit use of active logs during system initialization to
ensure transactional consistency. If a database or application is shut down normally,
consistency is established quickly. However, if a database or application terminates
abnormally, the restart process takes longer, and is dependent on the number and
size of the transactions that were in progress at the time of termination.
A replica image created from a running database or application without any
preparation is considered to be restartable. This is similar to the state encountered
during a power failure. As the application starts, it completes committed transactions
and rolls back uncommitted transactions to achieve transactional consistency.
196
◆
Disaster recovery—The process of rebuilding data from a backup image and applying
subsequent logs to update the environment to a designated point of consistency. The
steps required to establish recoverable copies of data are dependent on the
applications being protected.
◆
Roll-forward recovery—In some cases, it is possible to apply archive logs to a
database management system (DBMS) image to roll it forward to a specific point in
time. This capability offers a backup strategy that consists of a baseline image
backup, and archive logs to establish the recovery point.
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◆
Recovery point objective (RPO)—The consistency point to be established after a
failure. It is determined by the acceptable amount of data loss between the time the
image was created and the time a failure occurs.
◆
Recovery time objective (RTO)—The maximum time to recover data after the
declaration of a disaster. It includes the time taken to:
• Provision power and utilities
• Configure server software and networking
• Restore data at the new site
• Roll the environment forward and validate data to a known point of consistency
The following DR preparations made ahead of time reduce or eliminate delays in data
recovery:
◆
Establish a hot site with preconfigured servers.
◆
Implement a storage replication solution to ensure that applications start with current
data.
◆
Integrate that solution to provide intelligence to recover the entire infrastructure with
consideration for boot order and application and infrastructure dependencies.
Each RTO solution has a different cost profile. It is usually a compromise between the cost
of the solution and the potential revenue loss when applications are unavailable.
Design considerations for DR and data restart
The effect of data loss or application unavailability varies from business to business. The
tolerance for each determines the metrics and requirements for the DR solution.
When evaluating a solution, ensure that the RPO and RTO requirements of the business
are met. In addition, consider the operational complexity, cost, and ability of the solution
to return the entire business to a point of consistency. Each of these aspects is discussed
in the following sections.
Testing the solution
A DR solution requires tested, proven, and documented procedures. Operational test
procedures are often different from disaster recovery procedures.
Operational procedures are clearly documented. They are executed periodically to
simulate an actual DR scenario and verify that they are up to date.
Geographically distributed vSphere environments
The integration of VNX storage system replication products and VMware technologies
provides cost-effective DR and BC solutions. SRM provides the ability to establish a
verifiable runbook to automate and prioritize service recovery after a failover. Some of
these solutions are discussed in the following sections.
Introduction
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Using VMware vSphere in Data Restart Solutions
EMC remote replication technology overview
Business continuity solutions for production vSphere environments require offsite or
remote replication to ensure that reliable copies are created at a secondary location.
Active data replication with EMC technologies in conjunction with SRM offers seamless
solutions to automate virtual machine failover and resumption of applications and
services at the remote location.
VNX offers advanced data replication solutions to help protect file systems and LUNs. In
the event of a disaster, an environment failover to the remote location is accomplished
with minimal administrator intervention.
EMC replication options allow objects to be grouped together and managed as a single
session, or managed independently with different service levels and options for
synchronous and asynchronous remote storage updates. WAN bandwidth, RPO, and data
change rate drive the update frequency.
EMC provides the following replication options for VNX Storage systems:
◆
EMC Replicator offers native asynchronous replication for NFS datastores.
◆
EMC MirrrorView offers native synchronous and asynchronous replication for VNX
Block.
◆
EMC RecoverPoint offers synchronous and asynchronous out-of-band replication for
VNX block and file datastores.
Each replication technology is integrated with Replication Manager and SRM. Table 22
lists the DR and BC software options available for each storage device type.
Table 22 EMC replication options for VMware environments
Replication technology
NFS
EMC Replicator

EMC RecoverPoint CRR1

EMC MirrorView
VMFS
RDM




1. File system replication takes place at the LUN level.
EMC MirrorView and RecoverPoint provide a similar set of LUN and consistency group
replication capabilities. There are specific architectural differences, but from a business
process standpoint, the primary differences are functional. They relate to the number of
supported replicas, manageability, and ease of replica accessibility at the remote site.
EMC Replicator provides the most comprehensive solution to replicate NFS datastore file
systems. MirrorView and RecoverPoint support NFS, whereas Replicator is integrated with
VNX OE for File and provides the most flexibility for NFS.
Note: Replicator does not offer consistency groups for application consistency across
replicated file systems. To improve application consistency, place all virtual machines in a
single replicated file system, or replicate VNX OE for File LUNs with MirrorView or
RecoverPoint.
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The MirrorView driver is integrated with VNX OE for Block. It intercepts I/O sent to a source
device and mirrors these writes to a LUN on a remote VNX. MirrorView supports a
considerable number of replication sessions for one-to-one replication of many VNX LUNs.
It provides a good LUN-level replication solution between storage systems.
RecoverPoint is the most flexible replication technology, and provides a level of granularity
that is useful for integration with applications and business processes. RecoverPoint
offers a significant number of point-in-time copies (bookmarks), which provide the
flexibility to establish precise point-in-time images of the virtual storage devices.
EMC Replicator
EMC Replicator offers native file system replication for NFS datastores. Replicator is an
asynchronous replication solution that performs local or remote file system replication
within or between VNX systems. Replicator keeps remote file systems consistent with the
production environment for more than1,024 separate file system sessions for each VNX
Data Mover.
User-specified update periods define the interval at which Replicator updates the remote
file system. By default, a new delta set of accumulated changes is sent to the remote
system every 10 minutes. At the remote site, delta sets are played back to update the
remote file system. Replication sessions are customized with different update intervals
and quality-of-service settings to prioritize updates between NFS datastores.
EMC Replicator operates at the file system level. Therefore, it encapsulates all of the
virtual machines and files contained within an NFS datastore. It is a good practice to group
virtual machines with similar protection requirements to improve the reliability and
efficacy of the DR solution. Organize virtual machines at a file system level to facilitate
prioritization of DR policies in accordance with RPOs.
Replicating a NAS file system
Complete the following steps in Unisphere for remote file system replication:
1. In Unisphere, click Data Protection.
2. Click File Replication Wizard - Unisphere.
The Replication Wizard appears.
3. Complete the following steps, as shown in Figure 155 and Figure 156.
a. Select File System as the replication type.
b. Select Ongoing File System Replication to display the list of destination VNX
network servers.
c. Select the destination VNX system to create a read-only, point-in-time copy of a
source file system at the destination.
Note: The destination can be the same Data Mover (loop back replication), another Data
Mover in the same VNX cabinet, or a Data Mover in a different VNX cabinet.
d. Select the network interface to transfer the replication delta sets.
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Replicator requires a dedicated network interconnect between the source and
destination Data Movers. The wizard defaults to the first configured interface in the
list. Select the most appropriate interface to support replication between Data
Movers.
Figure 155 Data replication wizard
e. Specify a name for the replication session.
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f. Select the source file system to replicate to the remote location.
Figure 156 Replication wizard (continued)
g. Select a file system at the destination to support the replication session. If a file
system does not exist, create one, and then click Next.
Note: When Replicator is used to create a destination file system, it assigns the
name and the size of the destination file system based on the properties of the
source file system. Administrators select a storage pool for the destination file
system, and a storage pool for checkpoints. Assign a descriptive name with an
identifier, such as “DR” to help identify the replication relationship.
h. Select the interval at which to update the secondary site.
After the file systems are synchronized, the remote image transitions to an operational
read-only state. To use an NFS datastore at the remote location, mount the file system as
read/write by using any one of the following options:
◆
Initiate a failover
◆
Terminate the replication session
◆
Reverse the replication
This action promotes the storage devices at the remote location. It collects changes from
that environment, and applies them to the previous source location.
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After the file system is mounted as read/write, present it to the ESXi host and manually
register the virtual machines.
EMC MirrorView
EMC MirrorView supports options for synchronous and asynchronous replication of VNX
block storage between separate VNX storage systems. Replication data is transported over
Fibre Channel or iSCSI connections established between the storage systems. Protection
is assigned to individual LUNs or to a consistency group.
MirrorView LUN replication
In an ESXi host environment, VMFS datastore LUNs are replicated to establish a
synchronous datastore copy at a remote location. Secondary devices undergo an
initialization period to establish a block-for-block image of the source device. MirrorView
has two usable LUN states—synchronized and consistent. In a synchronized state, the
remote LUN is an identicial block-for-block copy of the source LUN. In a consistent state,
the remote LUN is synchronized, but has changed state because the mirror received
updates that are not applied to the LUN. The time period that establishes when a mirror
transitions from the consistent state to the synchronized state after an update is called the
quiesce threshold. The default value is 60 seconds of no host I/O to the mirror. A LUN or
consistency group at the remote location is promoted and used by ESXi when it is in either
of these states.
For multiple LUNs, it is a good practice to use a consistency group. Table 23 lists the
MirrorView limits for the VNX platforms.
Table 23
VNX MirrorView limits
VNX5100
VNX5300
VNX5500
VNX5700
VNX7500
Maximum number of
mirrors
128
128
256
512
1024
Maximum number of
consistency groups
64
64
64
64
64
Maximum number of
mirrors per consistency
group
32
32
32
64
64
MirrorView consistency group
A MirrorView consistency group is a collection of mirrored devices that are treated as a
single object within a VNX storage system. Operations such as synchronization,
promotion, and fracture are applied to all components of the consistency group. If an
event impacts the state of the consistency group, I/O is suspended to all components of
the consistency group to preserve write-ordered I/O to the LUNs and the applications they
serve.
All members of a consistency group are owned by different storage processors, but they
are on the same VNX storage system.
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Although synchronous and asynchronous mirrors are supported on consistency groups, all
LUNs in a consistency group are protected by the same replication mode. VNX supports 32
LUNs per consistency group for MirrorView (synchronous and asynchronous). Figure 157
shows an example of a consistency group with four LUNs. Use MirrorView consistency
groups with SRM configurations.
Figure 157 Preserving dependent-write consistency with MirrorView consistency groups
In this example, a communication failure results in a fracture of the MirrorView link
between the storage processors on the local and remote VNX storage systems. At the
point of disruption, MirrorView fractures all LUN mirrors in the consistency group. While
the secondary images are fractured, updates to the primary volumes are not propagated
to the secondary volumes to preserve data consistency. At this time, the writes to the
production LUNs are tracked in a log called a write-intent log. After the error is corrected,
all the updates are applied to the consistency group on the remote system.
Asynchronous MirrorView
Asyncrhonous MirrorView (MV/A) is a method used to replicate up to 256 LUNs between
VNX systems. With MV/A, host writes are acknowledged immediately and buffered at the
source VNX. At an administrator-defined interval, MirrorView creates a differential LUN
view and copies the changed blocks to the remote VNX to create consistent, write-ordered,
point-in-time copies of the production LUN. A gold copy of the target data is created prior
to the source or target updates. This copy preserves the data on the target side in case the
transfer is disrupted.
The asynchronous nature of MV/A replication implies a non-zero RPO. MV/A is designed to
provide customers with an RPO greater than or equal to 30 minutes. There are no distance
limitations between the source and target VNX storage systems.
Synchronous MirrorView
Synchronous MirrorView (MV/S) provides synchronous replication for LUNs or consistency
groups and ensures that each I/O is replicated to a remote system. Synchronous
replication for vSphere maintains lockstep consistency between the primary and
secondary storage locations. Write-operations from the virtual machine are not
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acknowledged until both VNX arrays have a copy of the data in their write caches. These
updates incur a propagation delay resulting from the distance and quality of the network.
As a result of that delay, MV/S is not suitable for locations separated by distances greater
than 100 kilometers.
Setting up MirrorView replication
Complete the following steps to set up MirrorView replication in Unisphere. When
configuring MirrorView, use the Virtualization tab in Unisphere or the VSI Storage Viewer
feature to identify LUN numbers and their relationships to the VMFS datastores and RDM
devices, as shown in Figure 158.
Note: The process and commands to configure synchronous and asynchronous MirrorView
replication are very similar. Specify the -async argument for asynchronous replication.
Figure 158 EMC Unisphere interface
1. From the Unisphere Data Protection window, select Manage Mirror Connections.
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2. Identify the Peer Storage System and enable the MirrorView connection between the
two systems as shown in Figure 159.
Figure 159 Enable MirrorView between VNX systems
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3. Use the Unisphere MirrowView LUN wizard to select the source LUNs and establish a
remote mirror at the recovery site as shown in Figure 160.
Figure 160 MirrorView Wizard - select source LUNs
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4. Select the remote storage pools to use for the MirrorView session as shown in
Figure 161.
Figure 161 MirrorView Wizard - select remote storge
5. Promote the secondary image at the DR site as shown in Figure 162.
Figure 162 Promote mirrored LUN
Note: When a secondary image is in a synchronized or consistent state, SnapView clones
or snapshots provide the ability to create consistent, point-in-time copies of the image
without promoting it and disrupting the MirrorView session.
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Figure 163 shows a schematic representation of a business continuity solution that
integrates VMware vSphere and MirrorView. The figure shows two virtual machines
accessing VNX LUNs as RDM volumes.
The solution provides a method to consolidate the virtual infrastructure at the remote site.
Because virtual machines can run on any ESXi host in the cluster, fewer ESXi hosts are
required to support the replicated virtual machines at the remote location.
Figure 163 Business continuity solution using MirrorView/S in a virtual infrastructure with VMFS
Failover MirrorView LUNs to a remote site using CLI
MirrorView LUNs or consistency groups are activated at the secondary site during the
failover process. The result is that all devices are transitioned to a writeable state and are
available to restart applications in that environment.
1. In a planned failover, disable or shut down the VNX at the production site before
performing the failover tasks.
2. To prevent data loss, synchronize secondary MirrorView/S LUNs before starting the
failover process.
3. Shut down the applications at the production site, and update the secondary image
manually.
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4. Right-click a consistency group and select Synchronize to synchronize all LUNs as
shown in Figure 164.
Figure 164 Synchronize MirrorView LUNs
MirrorView LUN synchronization performs the following changes:
• Sets the primary images on the production site to write-disabled.
• Reverses the mirror relationship of the devices. The devices at the remote site
assume the primary role and are set to write-enabled.
• Resumes the MirrorView link to allow updates to flow from the remote data center
to the production data center.
• Registers and powers on the virtual machine from the vSphere client or command
line utilities.
EMC RecoverPoint
EMC RecoverPoint provides local and remote LUN replication.
RecoverPoint consists of the following components:
◆
Continuous Data Protection (CDP) for local replication
◆
Continuous Remote Replication (CRR) for remote replication
◆
Continuous Local and Remote Replication (CLR), which is a combination of the two, for
sequential, remote, and local replication of the same LUN.
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Figure 165 provides an overview of the RecoverPoint architecture.
Figure 165 RecoverPoint architecture overview
Administrators use RecoverPoint to:
◆
Support flexible levels of protection without distance limitations or performance
degradation. RecoverPoint offers fine-grain recovery for VMFS and RDM devices that
reduce the recovery point through frequent updates to the replica devices.
◆
Replicate block storage to a remote location through a cluster of tightly coupled
servers.
◆
Use write splitters that reside on the VNX arrays or hosts in the SAN fabric. The write
splitter copies write I/Os destined for the ESXi datastore volumes and sends them to
the RecoverPoint appliance. The RecoverPoint appliance transmits them to the remote
location over IP networks as shown in Figure 165.
◆
Provide a full-featured replication and continuous data protection solution for VMware
ESXi hosts. For Remote Replication, RecoverPoint CRR uses small-aperture snapshot
images to provide a low RPO, or asynchronous replication with a small RPO to provide
VMware protection and guarantee recoverability with little or no data loss.
Virtual machine write splitting
For VMware environments, RecoverPoint provides a host-based write splitter to support
application integration for Windows virtual machines. The driver filters write operations to
each protected RDM volume and ensures that each write command is sent to the
RecoverPoint appliance. Since the splitter or KDriver runs on the virtual machine, only SAN
volumes attached to virtual machine in physical RDM mode (pRDM) are replicated by
RecoverPoint.
RecoverPoint VAAI support
vSphere version 5.1 and later provides full support for VAAI with the VNX splitter. Table 24
illustrates the minimum releases for VAAI support with the VNX RecoverPoint splitter.
Versions of the VNX splitter or VNX OE for Block code prior to those listed in the table
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support only Hardware Accelerated Locking (ATS) for block storage devices. ATS is the only
SCSI command supported for VNX and RecoverPoint versions previous to those listed in
Table 24. If running a prior version, SCSI commands other than ATS are rejected and revert
to the host for processing.
Table 24 Minimum revision levels for VAAI support with VNX RecoverPoint splitter
VAAI Primitive
VNX Revision level
Notes
Hardware assisted
locking
VNX splitter 3.4 with FLARE 31 and later
Supported
Block zeroing
VNX splitter 3.4 with FLARE 31 and later
Supported
Full copy
VNX splitter 3.4 with FLARE 31 and later
Supported without
performance enhancement
Uncopy
VNX splitter 3.5 SP1 and later
Supported
Note: The RecoverPoint SAN splitter Storage Services Interface earlier than version 4.2(3K)
does not support VAAI SCSI commands. For SAN splitters prior to SSI 4.2(3K), disable VAAI
to use the SAN splitter.
Figure 166 illustrates the Data Mover advanced settings interface for VAAI Hardware
Accelerated Move (XCOPY) and Hardware Accelerated Init (Write-Same). Set the value of
these parameters to zero to disable XCOPY and Write-Same support on the ESXi host.
Figure 166 Disabling VAAI support on an ESXi host
RecoverPoint provides consistency groups to assign VNX storage devices to ESXi hosts.
Each consistency group is made up of LUNs that are protected. A journal LUN (volume) is
also assigned to each consistency group to maintain the bookmarks and the various
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states provided with RecoverPoint. Separate VNX storage groups are created for the
RecoverPoint appliance and ESXi host HBAs. LUNs that require protection are assigned to
both storage groups.
Configure the consistency groups, apply policies, and manage storage access through the
RecoverPoint management UI or CLI.
Note: All virtual disks that constitute a virtual machine are a part of the same consistency
group. If application consistency is required when using RDMs, install the RecoverPoint
driver in the Windows guest OS. Table 19 on page 246 summarizes the support options
available with RecoverPoint for VNX replication.
Table 25
EMC RecoverPoint feature support
Splitter
Feature
Windows host write
splitter
Array-based write
splitter
Brocade/Cisco
Intelligent Fabric
write splitter
Supports physical RDM



Supports virtual RDM



Supports VMFS



Supports VMotion®



Supports HA/DRS



Supports vCenter Site Recovery
Manager



Supports P2V replication
RDM/P only
RDM/P and VMFS
RDM/P and VMFS
Supports V2V replication
RDM/P only
RDM/P and VMFS
RDM/P and VMFS
Supports guest OS boot from
SAN
RDM/P only
RDM/P and VMFS
RDM/P and VMFS
Supports ESXi boot from SAN



Maximum number of LUNs
supported per ESXi hosts
255 (VMware
restriction)
N/A
N/A
Heterogeneous array support
EMC VNX, CLARiiON
CX, Symmetrix and,
selected third party
storage
EMC VNX and
CLARiiON CX3/CX4
EMC and third party



Shareable between
RecoverPoint clusters
RDM volume replication
Replication of RDMs requires the completion of management tasks in addition to those for
datastore replication of VMFS LUNs. RDM volumes are separate physical devices assigned
directly to the virtual machines without the hypervisor I/O path. As a result, the ESXi host
does not have a device ID or LUN signature to identify the device on the remote host. The
RDM device paths are preserved at the OS level to ensure OS and application integrity.
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EMC Replication Manager interacts with EMC replication technologies to manage the
remote replicas and preserve the device mappings of NTFS-formatted pRDM volumes.
Configuring remote sites for vSphere virtual machines with RDM
When an RDM is added to a virtual machine, a virtual disk file is created that maps the
logical virtual machine device to the physical device. The file contains the VNX LUN WWN
and LUN number of the device presented to the virtual machine.
The virtual machine configuration is updated with the name of the RDM volume and the
label of the VMFS datastore where the RDM volume resides. When the datastore that
contains the virtual machine is replicated to a remote location, it maintains the
configuration and virtual disk file information. However, the target LUN has a different
UUID that results in a configuration error if the virtual machine is powered on.
Snapshots and clone LUNs are used to validate the configuration because they are
presented to hosts or virtual machines without disrupting the replication session. They are
also beneficial for ancillary purposes such as QA or backup.
Maintaining device order
The most important consideration for RDM replication is to ensure that SCSI disks
maintain the same device order within the Guest OS. This requires precise mapping of the
VNX LUNs to the virtual machine at the secondary site.
Determine the device mapping for the ESXi hosts and document the disk order for the
devices presented to the virtual machines on the remote site. Table 26 shows an example
with three application data disks.
Table 26 VNX to virtual machine RDM
LUN number
Windows disk
Virtual device node
2
\\.\PHYSICALDRIVE2
SCSI (0:1)
3
\\.\PHYSICALDRIVE3
SCSI (0:2)
4
\\.\PHYSICALDRIVE4
SCSI (0:3)
These three VNX LUNs are replicated to a remote VNX. Exclude the boot device that
occupies SCSI target 0:0 and configure the virtual machine at the remote site to present
the following:
◆
Replicated LUN associated with LUN 2 as SCSI disk 0:1
◆
Replicated LUN 3 as SCSI disk 0:2
◆
Replicated LUN 4 as SCSI disk 0:3
Use a copy of the source virtual machine configuration file instead of replicating the
VMware file system.
Creating copies of the production virtual machine
Complete the following steps to create copies of the production virtual machine by using
RDMs at the remote site:
1. Create a directory within a cluster datastore at the remote location to store the
replicated virtual machine files.
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Note: Select a datastore that is not part of the current replication configuration to
perform this one-time operation.
2. Copy the configuration file of the source virtual machine to the directory.
3. Register the cloned virtual machine through the vSphere Client or the service console.
4. Configure the ESXi hosts at the remote site to use the secondary MirrorView LUNs as
RDM devices.
5. Use the vSphere Client or service console to power on the virtual machine at the
remote site.
Note: Because these tasks present configuration risks, they are best supported with SRM
or through an automated Power Shell scripted utility.
Starting virtual machines at a remote site after a disaster
Complete the following steps to restart virtual machines at the remote site with the
replicated copy of the data:
1. Verify that the replicas are in a synchronized or consistent state.
2. Promote the replica LUNs, file systems, or consistency groups at the remote site.
Promoting a LUN changes the state of the device to write-enabled, which makes it
usable by the ESXi hosts in the remote environment.
3. Add the promoted devices to the ESXi storage groups to allow the ESXi hosts access to
the secondary images.
4. Rescan the SCSI bus to discover the new devices for block storage.
5. Power on the cloned virtual machines with the vSphere Client or the CLI.
Configuring remote sites for virtual machines using VMFS
The management of virtual machines on a replicated VMFS volume is very similar to that of
an RDM volume. Complete the following steps to create virtual machines at the remote
site:
1. Promote the secondary LUN images to make them write-enabled and accessible by the
VMware ESXi cluster group at the remote data center.
2. Use the vSphere Client to initiate an SCSI bus rescan after surfacing the target devices
to the VMware ESXi hosts.
3. Use the vSphere Client Add Storage wizard to select the replicated devices that
contain the copy of the VMware file systems. Select the Keep existing signature option
for each LUN copy. After all the devices are processed, the VMware file systems are
displayed on the Storage tab of the vSphere Client interface.
4. Browse the datastores with the vSphere Client, to identify and register the virtual
machines.
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Note: Duplicate virtual machine names can be unintentionally introduced when using
replication services. vCenter does not allow duplicate names within the same
datacenter. If a duplicate object name is encountered, assign a new virtual machine
name to complete the registration.
5. Verify that the following requirements are met to ensure that the virtual machines on
the ESXi hosts at the remote site start without any modification:
• The target ESXi host has the same virtual network switch configuration as the
source ESXi host. For example, the name and number of virtual switches are
duplicated from the source ESXi cluster group.
• All VMware file systems used by the source virtual machines are replicated.
• The minimum resource requirements of all cloned virtual machines are supported
on the target ESXi hosts.
• Peripheral devices such as CD-ROM and floppy drives are attached to physical
hardware, or set to a disconnected state on the virtual machines.
6. Power on the cloned virtual machines from vCenter or the command line when
required. If vCenter generates a msg.uuid.altered message, select the copied
option to complete the power-on procedure.
EMC Replication Manager
EMC Replication Manager (RM) supports all of the EMC replication technologies. RM
simplifies the creation and management of storage device replicas through Application
Sets. An Application Set includes the replication job details and any tasks required to
place applications running inside the virtual machines in a consistent state prior to
creating a replica of a virtual machine or datastore.
In a VMware environment, RM uses a proxy host (physical or virtual) to initiate
management tasks on vCenter and VNX. The RM proxy service runs on the same physical
or virtual host as the RM server.
Other requirements include:
◆
The proxy host is configured with:
• RM agent
• EMC Solutions Enabler for VNX Block
• Navisphere Secure CLI for VNX Block
• Administrative access to the VNX storage systems
◆
If application consistency within the guest virtual machine is required, install the RM
agent on the virtual machine.
◆
The environment has a proper DNS configuration to allow the proxy host to resolve the
hostnames of the RM server, the mount host, and the VNX Control Station.
EMC Replication Manager
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When an Application Set is initiated on a VNX device containing virtual machines, the RM
proxy sends a vCenter request to create VMware snapshots of all online virtual machines
that reside on the ESXi datastore. This step ensures that the resulting replica is OS
consistent. Figure 167 shows a NAS datastore replica in the RM.
Figure 167 RM protection for NFS datastores and virtual machines
RM includes the option to mount a replicated device to another ESXi host. After a failover
operation, RM performs all the necessary steps to change the device state and mount and
import the datastore into the ESXi host environment. Additional administrative tasks, such
as starting virtual machines and applications, are defined within the Application Set and
automated through RM.
Unisphere provides the option to administratively failover file systems to a remote
location. After the failover, the file systems are mounted on the remote ESXi host. Virtual
machines that reside in the datastores are optionally registered through the vSphere
Client.
Complete the following steps to register virtual machines in the vSphere Client:
1. Use the datastore browser to select a virtual machine folder.
2. Locate and right-click the configuration (VMX) file, and then select Add to Inventory to
register the virtual machine with an ESXi host as shown in Figure 168.
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Note: The ESXi host names for virtual machine networks, VMkernel, and similar
properties are identical to the source. Inconsistent network names result in
accessibility issues.
Figure 168 Using the vSphere client to register a virtual machine with ESXi
Automating site failover with SRM and VNX
VMware vCenter Site Recovery Manager (SRM) provides a standardized framework to
automate VMware site failover. SRM is integrated with vCenter and EMC storage systems.
It is managed through a vCenter client plug-in that provides configuration utilities and
wizards to define, test and, execute failover processes called recovery plans. A recovery
plan defines which assets are failed over, and the order in which they are restored when
the plan is executed. SRM includes capabilities to execute pre- and post-failover scripts to
assist in preparing and restoring the environment.
SRM testing
An attractive feature of SRM is provided through recovery plan validation tests, which
allow a failover to be simulated in advance of an actual site outage. During the recovery
plan validation test, production virtual machines at the protected site continue to run, and
the replication sessions remain active for all the replicated LUNs or file systems.
When the test failover ccommand is run, SRM simulates the storage device failover by
issuing commands to the VNX to generate writeable snapshots at the recovery site. The
snapshot LUNs or file systems are mounted to the ESXi hosts. Virtual machines are
powered on and optional post-power-on scripts are run.
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The test recovery executes the same steps as a failover does. Therefore, a successful test
process increases the likelihood of a successful failover. Companies realize a greater level
of confidence when they know that their users are trained on the disaster recovery process
and execute it correctly each time.
Administrators can add test-specific customization to the workflow for the test failover to
handle cases where the test differs from the actual failover scenario. If the virtual
machines are powered on successfully, the SRM test process is complete. If necessary,
users can start applications and perform validation tests. Run the Cleanup task to revert
the environment to the pretest state and remove any temporary storage devices that were
created as part of the test, as shown in Figure 169.
Figure 169 SRM recovery plan summary
Actual failover, or Recovery as it is called in SRM, is similar to the test failover, except that
rather than using snapshots, the actual storage devices are failed over to a remote
location. LUNs and file systems at the recovery site are brought online, and the virtual
machines are powered on.
During failover, SRM powers off active virtual machines at the protected site to avoid
having active virtual machines at both sites. This task will not complete if the protected
site is not operational.
EMC Storage Replication Adapter
SRM uses the data replication capabilities of the underlying storage system through an
interface called a Storage Replication Adapter (SRA). SRM supports SRAs for EMC
Replicator, EMC MirrorView, and EMC RecoverPoint.
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EMC SRA is a software package that enables SRM to implement disaster recovery for
virtual machines by using VNX storage systems that run replication software. SRA-specific
scripts support array discovery, replicated LUN discovery, test failover, failback, and actual
failover. Disaster recovery plans provide the interface to define failover policies for virtual
machines running on NFS, VMFS, and RDM storage.
Figure 170 shows an example of SRM configuration in vCenter.
Figure 170 VMware vCenter SRM configuration
SRM protection groups at the protected site
A protection group consists of one or more replicated datastores that contain virtual
machines and templates. It specifies the items to be transitioned to the recovery site in
the event of a disaster. A protection group establishes virtual machine protection and
maps virtual machine resources from the primary site to the recovery site. A one-to-one
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mapping exists between an SRM protection group and a VNX or RecoverPoint consistency
group. Figure 171 illustrates the configuration of a protection group that uses a
MirrorView LUN consistency group.
Figure 171 Creating an SRM protection group
Note: In cases that do not use a one-to-one mapping—for example where RecoverPoint is
used to protect a database application with separate consistency groups for binaries, user
databases, and system databases—the SRM protection group consists of multiple
consistency groups.
If the VNX model does not support the number of devices being protected within a
protection group, create multiple VNX consistency groups for each protection group.
Note: The maximum number of consistency groups allowed per storage system is 64. Both
MirrorView/S and MirrorView/A count toward the total.
The VNX Open Systems Configuration Guide, available on EMC Online Support, provides
the most up-to-date synchronous and asynchronous mirror limits.
SRM recovery plan
The SRM recovery plan is a list of steps required to switch the operation of the datacenter
from the protected site to the recovery site. The purpose of a recovery plan is to establish a
reliable failover process that includes prioritized application recovery. For example, if a
database management server needs to be powered on before an application server, the
recovery plan starts the database management server, and then starts the application
server. After the priorities are established, test the recovery plan to ensure the order of
activities is correctly aligned to continue running the business at the recovery site.
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Recovery plans are created at the recovery site, and are associated with one or more
protection groups created at the protected site. Multiple recovery plans for a protection
group are defined to handle applications and virtual machines with differing recovery
priorities.
The options for recovery plan management are:
◆
Test—Tests the failover of the storage and virtual machine environment using
temporary snapshot-based storage devices.
◆
Cleanup—Reverts the protected and recovery environments back to their pretest
states. It also removes the temporary storage created to support the virtual machines
at the recovery site.
◆
Recovery—Provides two options: migration and disaster. The migration option shuts
down virtual machines from the protected site and synchronizes the storage between
the two VNX systems to perform a graceful migration of virtual machines from the
protected site to the recovery site. The disaster option performs the same storage
tasks but does not attempt to shut down the virtual machines at the protected site.
◆
Reprotect—Re-establishes protection of virtual machines after a planned migration.
Protection is established at the failover site, and virtual machines are protected at a
secondary site that includes the previous production site.
Testing the SRM recovery plan at the recovery site
Test the SRM recovery plan to verify that it performs as expected. Figure 172 shows a
sample recovery plan.
Figure 172 Testing the recovery plan
Click Test to test the recovery plan. During the test, the following events occur:
◆
Production virtual machines are shut down.
◆
SnapView sessions are created and activated using the existing snapshots.
◆
All the resources created within the SRM protection group are re-created at the
recovery site.
◆
Virtual machines power on in the order defined in the recovery plan.
In SRM release 4, after all tasks in the recovery plan are complete, SRM pauses until the
results are verified. After the test results are verified, click Continue to revert the
environment to its production state.
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SRM release 5 provides the Cleanup option to revert the recovery environment to the
pretest configuration and remove temporary storage devices created as part of the test.
Figure 173 shows the cleanup of a sample recovery plan.
Figure 173 Recovery plan Cleanup
The VMware vCenter SRM Administration Guide, available on EMC Online Support and on
the VMware website, provides more information on SRM recovery plans and protection
groups.
Executing an SRM recovery plan at the recovery site
The execution of an SRM recovery plan is similar to testing the environment, with the
following differences:
◆
Execution of the SRM recovery plan is a one-time activity.
◆
SnapView snapshots are not involved when the SRM recovery plan runs.
◆
The MirrorView/RecoverPoint/Replicator secondary copies are promoted as the new
primary production LUNs.
◆
Restoring to the production environment requires the execution of the reprotect
feature of SRM 5. Reprotect in SRM 5, along with the test, cleanup, and failback
features, provide capabilities beyond DR, such as data center load-balancing and
migration support.
◆
In the absence of any of the failback options listed above, manual steps are required
to restore the protected site after executing a recovery plan.
Note: Do not execute an SRM recovery plan unless it is part of a validation test or a
disaster has been declared.
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Figure 174 shows a completed recovery plan.
Figure 174 SRM recovery plan with EMC MirrorView
SRM failback and reprotect
SRM failback is the process of restoring the protected VMware configuration after the
protected environment storage infrastructure and vSphere environment are restored to a
state that supports the application data.
SRM 5 provides an integrated reprotect feature that re-creates virtual machine and storage
resource relationships between the site where the environment was recovered, and the
previous protected site that supported the production environment after a failover.
Use the reprotect feature to establish a new relationship between the sites, with the two
environments reversing roles. The recovery site becomes the protected site, and the
protected site becomes the recovery site.
SRM reprotect works with all EMC storage replication adapters to re-establish or reverse
the storage replication sessions between the two sites.
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Reprotect provides the functionality to re-establish the protection relationships and
storage configuration between the two environments so that the storage devices at
recovery site are immediately protected after a failover occurs. After reprotect tasks are
complete, SRM recovery plan tests are performed to validate the configuration prior to
initiating a recovery to the production site, as shown in Figure 175.
Figure 175 SRM reprotect
Best practices for SRM with VNX
Observe the following recommendations and cautions:
224
◆
Install VMware tools on the virtual machines targeted for failover. If the tools are not
installed, an error event is generated in the recovery plan when SRM attempts to shut
down the virtual machine. Click the History tab to view any errors.
◆
Enable SnapView on the arrays with snapshots at both the primary and secondary
sites to test failover and failback.
◆
Create alarms to announce the creation of new virtual machines on the datastore so
that the new virtual machines are added to the mirrors in the SRM protection scheme.
◆
Complete the VNX-side configurations (MirrorView setup, snapshots creation, and so
on) before installing SRM and SRA.
◆
Ensure that there is enough disk space configured for both the virtual machines and
the swap file at the secondary site so that recovery plan tests run successfully.
◆
If SRM is used for failover, use SRM for simplified failback. Manual failback is a
cumbersome process where each LUN is processed individually, including selecting
the appropriate device signature option in vSphere on primary ESXi hosts. SRM
automates these steps.
◆
Testing a recovery plan only captures snapshots of the MirrorView secondary image; it
does not check for connectivity between the arrays or verify whether MirrorView works
correctly. Use the SRM connection to verify the connectivity between the virtual
machine consoles. Use SRM Array Manager or Unisphere to check the connectivity
between arrays.
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Summary
Table 27 lists the data replication solutions available for different types of VNX storage
presented to an ESXi host.
Table 27 Data replication solutions
Type of virtual object
Replication
NAS datastore
• EMC Replicator
• EMC Replication Manager
• VMware vCenter SRM
VMFS/iSCSI
•
•
•
•
RDM/iSCSI (physical)
• EMC RecoverPoint
• EMC MirrorView
• VMware vCenter SRM
RDM/iSCSI (virtual)
• EMC RecoverPoint
• EMC MirrorView
• VMware vCenter SRM
EMC RecoverPoint
EMC MirrorView
EMC Replication Manager
VMware vCenter SRM
Summary
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CHAPTER 5
Data Vaulting and Migration
This chapter presents the following topics:
◆
◆
◆
◆
◆
◆
◆
Introduction ..........................................................................................................
Using SAN Copy with VMware file systems.............................................................
Using SAN Copy with RDM virtual disks .................................................................
Using SAN Copy for data vaulting ..........................................................................
Importing Storage into the remote environment ....................................................
Using SAN Copy to migrate data to VNX arrays .......................................................
Summary ..............................................................................................................
Data Vaulting and Migration
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Introduction
A core value of virtualization is the ability to move applications and data freely throughout
the datacenter and networked environment. Data mobility enables you to move your data
where it needs to be, when it needs to be there. An application server and its data can be
encapsulated and transferred to another location in a relatively short period of time. This
capability saves time and IT resources, provides additional measures of data protection,
and enables improved collaboration.
The evolution of cloud computing has accelerated the trend toward data and application
mobility, and established a need for periodic and cyclical migration processes to satisfy a
variety of business purposes.
Regulatory compliance might require that multiple copies of data be retained in a
protected facility for a specified period of time. The criticality of business information also
imposes strict availability requirements. Few businesses can afford protracted downtime
to identify and redistribute data to user groups. Data copy and migration are core
components of virtual datacenter management for tapeless backups, data vaulting, and
many other use cases.
These examples highlight the need for technologies and practices to simplify data
migration.
VMware provides Storage vMotion and Storage DRS to redistribute and migrate virtual
machines between datastores. However, these technologies do not provide an
enterprise-level solution for a full-scale migration of datastores from one storage location
to another that does not impact the production environment.
EMC offers technologies to migrate data between storage systems with minimal impact to
the ESXi operating environment. This chapter discusses SAN Copy™ and its
interoperability in vSphere environments with VNX block storage.
Using SAN Copy with VMware file systems
SAN Copy is a VNX service that enables you to create copies of block storage devices on
separate storage systems. SAN Copy propagates data from the production volume to a
volume of equal or greater size on a remote storage array. SAN Copy provides the ability to:
◆
Create one-time LUN replicas on a separate system
◆
Perform LUN migration as part of a system upgrade process
◆
Perform periodic updates between storage systems for centralized data vaulting or
archiving
SAN Copy performs replication at the LUN level and creates copies of LUNs that support
VMFS datastores or RDM volumes.
Like other LUN cloning and replication technologies discussed in Chapter 2, “Cloning
Virtual Machines,” the contents of the file system or the RDM volume are encapsulated
within the replica LUN. The replica is presented to another host where the virtual machines
and data can be imported into the environment.
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Note: Avoid using SAN Copy with multiextent file systems. If a VMFS file system contains
multiple extents, then all LUNs must be replicated to the target location and presented in
the same device order.
To ensure application consistency, shut down the virtual machines that access the
spanned VMware file system before you start the SAN Copy session. If the virtual
machines cannot be shut down, use SnapView™ to create crash-consistent LUNs and use
the SnapView LUN as the source for the SAN Copy session.
Using SAN Copy with RDM virtual disks
RDM volumes configured for physical compatibility mode provide direct VNX LUN access to
the virtual machine. The virtual machine I/O bypasses the VMkernel and issues SCSI
commands directly to the VNX LUN.
Since the guest operating system can issue SCSI commands to the storage array through
an RDM LUN, the virtual machine uses application utilities and storage commands to
prepare the LUNs before starting the SAN Copy session. When migrating data from an RDM
volume, place applications in a hot standby mode or shut them down to ensure
application consistency.
Using SAN Copy for data vaulting
SAN Copy has the following modes of operation:
◆
Full mode performs a complete re-silvering of the target device during each SAN Copy
operation.
◆
Incremental mode performs periodic updates to an existing replica. It provides the
foundation for data vaulting solutions. Offsite copies are periodically refreshed to
maintain updated content from the production environments.
A schematic representation of the data vaulting solution is shown in Figure 176.
Incremental SAN Copy uses SnapView technology to establish a consistent image of the
production LUN state and to buffer data before it is copied to the target array. SnapView
uses copy-on-write processing to maintain image versions.
Note: Consider the amount of I/O overhead when using Incremental SAN Copy in
environments with high rates of data change.
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Use a SnapView Clone LUN with SAN Copy to eliminate copy-on-write overhead. SnapView
Clone establishes an independent replica to alleviate I/O to the production LUN. A clone
refresh is required to update the SAN Copy replica LUN.
Figure 176 Data vaulting with Incremental SAN Copy
Using SAN Copy for data vaulting of VMware file systems
1. Migrate the LUN:
Note: This process applies to any VMFS or RDM LUN.
a. Identify all the devices to be copied.
b. Use Unisphere or the VSI Storage Viewer feature to identify the LUN that supports a
VMFS datastore or RDM volume.
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c. Select the SAN Copy target devices on the remote storage system. If multiple VNX
systems are configured in a domain, storage devices on the remote storage system
are visible in the SAN Copy Wizard, as shown in Figure 177.
Figure 177 Using Unisphere or Storage Viewer to identify source LUNs
d. For non-VNX storage systems, identify the LUN number and the 128-bit WWN
number that uniquely identify the SCSI devices. After you identify the source and
destination LUNs, connect to the Unisphere SAN Copy configuration interface.
Note: There are multiple ways to determine the WWN. Use the management
software for the storage array and Solutions Enabler to obtain the WWN of devices
on supported storage arrays (Symmetrix, HDS, and HP StorageWorks).
2. Initiate the migration session and create a data vaulting solution:
a. In a SAN Copy configuration, VNX storage processor (SP) ports act as host initiators
that connect the source VNX to SP ports on the remote VNX system. Create a
storage switch zone including VNX SP WWNs from the source and target VNX
systems.
b. VNX does not allow unrestricted access to storage. Create a storage group to mask
the source VNX initiators with the VNX target LUNs. Use the storage array
management utility to give the VNX SP ports access to the appropriate LUNs on the
remote storage array.
c. Incremental SAN Copy sessions communicate with SnapView internally to keep
track of updates for a SAN Copy session. Before you create an Incremental SAN
Copy session, configure the SnapView-reserved LUN pool with the available LUNs.
The size and quantity of the reserved LUNs depend on the number of accumulated
changes to the source LUN between SAN Copy updates. If the rate of change is very
high, or if the updates between the source and destination are infrequent (perhaps
due to scheduling or bandwidth), increase the size of the reserved LUN pool.
d. Create an Incremental SAN Copy session between the source and destination LUNs
as shown in Figure 178 and Figure 179.
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e. Specify the attributes for the SAN Copy session:
– SAN Copy session name
– WWNs of the source and destination LUNs
– Throttle value, latency, and bandwidth control value of the storage system
interconnect.
Note: SAN Copy establishes a latency value by sending test I/O to the target. Do
not alter the latency value.
Establishing a SAN Copy session does not trigger data movement. Initiating the
session performs a series of validation tests to ensure that the VNX SP ports can
access the remote devices, and that the capacity of each remote device is equal to
or greater than the source devices.
– Activating the session establishes a point-in-time copy of the data from the
source devices and propagates it to the target devices.
– SAN Copy provides a throttle parameter to control the rate at which data is
copied between the source and target systems. A throttle value of 10 causes
SAN Copy to use all available system resources to speed up the transfer. You
can adjust the throttle value at any time after a session is created.
Creating an incremental SAN Copy session is shown in Figure 178 and Figure 179.
Figure 178 Creating an Incremental SAN Copy session
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Figure 179 Creating an Incremental SAN Copy session (continued)
f. After the copy process is complete, activate the LUNs at the remote site in
Unisphere to make them available to the ESXi hosts.
Note: The target devices must remain inactive to continue to perform Incremental
updates. Create SnapView LUN snapshots and present them to the ESXi host to
allow the remote ESX environment to access the copies of the data.
g. Restart the existing SAN Copy session to perform an incremental update of the
remote device. Incremental updates dramatically reduce the amount of data that
must be propagated when the source volume has had very little change between
updates.
Using SAN Copy for data vaulting of virtual machines configured with RDMs
SAN Copy provides a storage array-based mechanism to create a consistent point-in-time
copy of virtual disks stored on VNX LUNs. For RDM LUNs, SAN Copy replicates only the
contents of the volume that have been modified by the guest, which is more efficient than
replicating multiple virtual disks.
Virtual machines configured with RDM volumes in physical compatibility mode are aware
of the presence of VNX devices when Navisphere CLI/Agent is installed. The virtual
machine has the ability to determine the devices to replicate with SAN Copy. Identify the
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devices that require protection and then configure SAN Copy to perform the replication of
raw devices in the same manner as described in “Using SAN Copy for data vaulting of
VMware file systems” on page 230.
Importing Storage into the remote environment
You can configure remote sites for vSphere virtual machines using VMFS or RDM.
Configuring remote sites for virtual machines using VMFS
Complete the following steps to create virtual machines at the remote site:
1. Enable ESXi host access to the remote LUN copy at the remote datacenter. Use a
snapshot of the LUN instead of the actual device to preserve the Incremental SAN Copy
capabilities.
2. Use unique virtual machine and datastore names to avoid name collisions. vCenter
does not allow duplicate object names (like virtual machine names) within a vCenter
datacenter.
3. Activate the LUN, assign it to the storage group of the ESXi cluster at the target site,
and perform a host bus rescan to identify the new devices.
4. Use the vSphere Client to add the storage devices where the replicated VMware file
system devices reside. Select Keep existing signature for each LUN. After all the replica
storage has been added, the VMFS datastores appear in vCenter under Host >
Configuration > Storage.
5. Browse the datastores to locate and register the virtual machines.
You can start the virtual machines at the remote site without modification if the following
configuration requirements are met:
◆
The target ESXi hosts use the same virtual switch configuration as the source ESXi
hosts. For example, the virtual switch and virtual machine network names must be
consistent with the source vCenter cluster.
◆
All VMware file systems used by the source virtual machines are replicated.
◆
The target ESXi host contains sufficient memory and processor resources to satisfy
admission control in DRS cluster configurations.
◆
Devices such as CD-ROM and floppy drives are attached to physical hardware or
disconnected from the virtual machines when they are powered on.
Configuring remote sites for vSphere virtual machines with RDM
When a LUN is assigned to a virtual machine as an RDM device, a new virtual disk file is
created within a VMware file system. This virtual disk file contains metadata that maps the
virtual disk to the physical SCSI device. The file includes information such as the device
ID, LUN number, RDM name, and the name of the VMware file system where the mapping
is stored. If the datastore that holds the virtual machine configuration and the RDM file is
replicated and presented to a different ESXi host, it is likely that the mapping file is not
valid because it references an inaccessible device. Therefore, use a copy of the source
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virtual machine configuration file to reconstruct the virtual machine at the remote
location. Use the VMX file to register the virtual machine, and remap the virtual machine
disk to the RDM replica in vCenter.
Note: The following procedure assumes that the source virtual machine does not have a
virtual disk on a VMware file system. The process to clone virtual machines with a mix of
RDMs and virtual disks is complex and beyond the scope of this document.
Complete the following steps to create a remote copy of a virtual machine with RDMs:
1. Create a folder in a datastore that resides on an ESXi host within the cluster at the
remote site. This folder contains the virtual machine configuration files for the
replicated virtual machine. Use a datastore that is not part of a replication session to
avoid the possibility that the files may be overwritten.
2. Copy the configuration files of the source virtual machine to the directory created in
Step 1. Use a command line utility like scp, or use the vSphere Client datastore
browser to complete this step.
3. From the remote vCenter environment, register the cloned virtual machine using the
VMX file copied in Step 2.
4. Generate RDMs on the target ESXi hosts in the directory created in Step 1. Configure
the virtual machine RDM virtual disks to use the remote copy of the devices.
5. Power on the virtual machine at the remote site and verify that the devices are
accessible within the guest OS.
Start the virtual machines with the procedure described in “Starting virtual machines at a
remote site after a disaster” on page 214.
Using SAN Copy to migrate data to VNX arrays
VMware storage migration is largely accomplished by Storage vMotion, which offers an
integrated solution to relocate virtual machines from an existing storage platform to a new
system as part of a platform upgrade.
The value of Storage vMotion as a migration solution is that it preserves the virtual
machine, datacenter, resource pool, and host configuration within the vCenter
environment. Storage vMotion in vSphere 5 includes support for multiple vMotion
interfaces, and offers the ability to perform simultaneous migrations between ESXi hosts.
In most cases Storage vMotion provides the best approach to system migration. However,
there are occasions when a migration is limited by time and/or process. This is addressed
by migrating the virtual machines at the datastore level. For example, large-scale LUN
migrations benefit from SAN Copy because it reduces resource utilization of the host.
Storage vMotion does not preserve RDM volumes. When a virtual machine with RDM LUNs
is migrated, the virtual disks are converted to VMFS as part of the process.
SAN Copy is frequently used to migrate LUNs to VNX. One of the major advantages of SAN
Copy is that it offers Incremental SAN Copy to prepopulate and validate the target
environment to limit service disruption during a cutover.
Using SAN Copy to migrate data to VNX arrays
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SAN Copy provides various modes of operation. In addition to the incremental copy mode,
SAN Copy supports the full copy mode where data from a supported storage system is
migrated to the VNX storage system. Complete the following steps to migrate VMware
virtual infrastructure data from SAN Copy-supported storage arrays to an EMC VNX storage
system:
1. Use the management interface of the source storage array to identify the WWNs of the
source devices.
2. Identify the target LUN on the VNX system. The capacity of the target LUN must be
equal to or greater than the source LUN.
3. Create a full SAN Copy session for the clone volume on the remote array. Figure 180
shows the necessary options to create a full SAN Copy session.
Figure 180 Creating a SAN Copy session to migrate data to a VNX
4. Shut down the virtual machines that use the devices being migrated to ensure
application consistency.
5. Start the SAN Copy session to initiate the data migration from the source devices to
the VNX devices.
6. Modify the VNX LUN masking to ensure that the ESXi hosts have access to the
migrated devices. Update the zoning information to ensure that the ESXi hosts have
access to the appropriate front end Fibre Channel ports on the VNX storage system.
Note: It is a good practice to maintain the source environment until the target
environment has been thoroughly validated. A convenient way to do that is to remove
the ESXi hosts from the storage group, while maintaining the LUN mapping. With this
approach, the previous configuration can be quickly restored by adding the hosts back
to the storage group if a problem is encountered.
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Data Vaulting and Migration
7. After the full SAN Copy session completes, perform an ESXi host bus rescan to
discover the VNX devices. The ESXi hosts recognize the VMFS volumes and populate
them into the ESXi hosts that are visible from the Storage tab in the vSphere Client.
8. Using the vSphere Client Datastore Browser, identify each virtual machine within the
migrated LUNs.
9. Register each virtual machine and power it on to ensure that the virtual machine boots
correctly and that applications running on the virtual machine function the same way
they did on the previous storage system.
SAN Copy provides a convenient mechanism to use storage array capabilities to accelerate
the migration when there is a significant amount of content to migrate. SAN Copy can
significantly reduce the downtime due to the migration of data to VNX arrays.
Migrating devices used as RDM
Use the procedure described in “Configuring remote sites for vSphere virtual machines
with RDM” on page 234.
RDM volumes contain unique device information that cannot be transferred. When an RDM
virtual disk is replicated to a new LUN, the virtual disk configuration is invalidated
because the RDM mapping file points to a device UUID that no longer exists for that virtual
machine.
Modification of the virtual machine virtual disk configuration impacts applications that
rely on the existing device path. RDM replication can be accomplished easily through the
vSphere Client if the source and destination device IDs are correctly mapped.
When the data for virtual machines containing RDM volumes is migrated to another VNX,
the disk configuration for the virtual machine must be modified to address the RDM
replica LUN. Failure to correct the device mapping results in a virtual machine that does
not boot correctly. Complete the following steps to ensure this does not occur:
1. Remove the existing RDM LUN from the virtual machine.
2. Disassociate the ESXi host with the LUNs being used as RDM volumes.
3. Re-create the RDM device mapping by using the canonical name of the replica device.
Present the device with the same ALU/HLU sequence, and add the device with the
same disk ID inside the guest virtual machine.
4. Rescan the ESXi hosts and establish the correct device mapping by using the vSphere
Client to associate the virtual machine with the appropriate migrated LUN.
5. Power on the virtual machines and confirm that the OS and applications function
correctly.
Summary
This chapter describes how to use SAN Copy as a data migration tool for vSphere. SAN
Copy provides an interface between storage systems for one-time migrations or periodic
updates between storage systems.
One of the unique capabilities of SAN Copy is that it is compatible with different storage
system types. Therefore, it is a useful tool to migrate data during storage system
upgrades, and to migrate from existing storage platforms to a VNX platform.
Summary
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Data Vaulting and Migration
The Migrating Data from an EMC CLARiiON Array to a VNX Platform using SAN Copy White
Paper, available on EMC Online Support, provides more information about data migration
with SAN Copy.
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