HP P4000 DSM for MPIO Deployment Guide

HP P4000 DSM for MPIO Deployment Guide
HP P4000 DSM for MPIO Deployment Guide
HP Part Number: AX696-96111
Published: September 2011
Edition: 1
© Copyright 2011, Hewlett-Packard Development Company, L.P.
Description of the HP P4000 DSM for Microsoft MPIO
The HP P4000 DSM for Microsoft MPIO provides enhanced MPIO functionality as follows:
•
Automatic creation of an I/O path to each storage system in the cluster on which the volume
resides, plus a path for the administrative connection.
•
Improved performance architecture over native MPIO solutions:
•
◦
Read I/Os are always serviced by a storage system that holds a copy of the data being
requested.
◦
Write I/Os are always serviced by a storage system that receives a copy of the data.
Remaining copies (replicas) of the data are forwarded to the appropriate storage system
based on the data protection level of the volume.
The ability to build a robust, fault-tolerant solution because an I/O path is built to every storage
system in the cluster. For example, in a cluster with five storage systems, HP DSM for
MPIO-connected volumes have six iSCSI MPIO connections to the SAN, one for each storage
system and one for the administrative connection. Five of the six connections could go offline,
and I/O would still be serviced.
The HP DSM for MPIO supports connecting multiple NICs in the application server to the SAN.
Configuring with multiple NICs improves fault-tolerant physical network connections in the server.
The HP DSM for MPIO can be used in a Multi-Site SAN with one or more subnets. In this configuration,
the HP DSM for MPIO will only build I/O paths to the storage systems that are in the same subnet as
the application server. Alternatively, you can assign an application server to a site. Application servers
assigned to a site connect only to storage systems in the same site. Both of these configurations permit
higher performance and lower network utilization by reducing the amount of I/Os that traverse the
WAN link.
NOTE: Refer to the instructions specific to Multi-Site SAN configurations in the rest of this chapter.
You can also refer to the HP P4000 Multi-Site HA/DR Solution Pack User Guide, available on the HP
P4000 Management Software DVD or on the HP P4000 Manuals page of the HP Business Support
Center website.
http://www.hp.com/support/manuals
In the Storage section, navigate to Disk Storage Systems→P4000 SAN Solutions→HP LeftHand P4000
SAN Solutions or HP StorageWorks P4000 G2 SAN Solutions, depending upon your product.
Using Microsoft DSM
Beginning with SAN/iQ software Version 9.0, you can use Microsoft DSM on your application servers.
For additional information about the Microsoft DSM, see the MPIO white paper available from the
Microsoft website:
http://www.microsoft.com/download/en/details.aspx?id=9787
When setting up the MPIO load balancing policy, use only the Fail Over Only or Round Robin options.
For more information, see “Setting the Microsoft DSM MPIO load balancing policy” (page 8).
Using VMware ESX Server native MPIO
With VMware ESX, use the native ESX MPIO. For more information, see http://h20195.www2.hp.com/
V2/GetDocument.aspx?docname=4AA3-0261ENW.
Best Practices
If MPIO is not required, then do not install the HP DSM for MPIO or do not enable the the Microsoft
MPIO service.
Description of the HP P4000 DSM for Microsoft MPIO
3
If currently using the HP DSM for MPIO, then upgrade to the latest version.
Recommended uses for HP DSM for MPIO:
•
For maximum possible performance for specified configurations.
•
With Multi-Site SAN storage clusters, the HP DSM for MPIO with site preference is recommended,
particularly if the inter-site link is significantly slower than local access. This configuration will
ensure that reads are performed with a local replica when one is available. This is particularly
useful for Microsoft clusters where a Microsoft cluster node is on each side of the inter-site link.
Configurations where the HP DSM for MPIO is not recommended:
•
For any volumes that are accessed by ESX and Windows initiators (as might be done for VMware
Consolidated backup) do not use the HP DSM for MPIO.
•
Large Hyper-V clusters (either large storage cluster or many server NICs).
•
Large storage clusters with simultaneous access to many volumes using the HP DSM for MPIO
may encounter the Microsoft limit of 255 iSCSI sessions. In this case, use Microsoft MPIO, which
uses fewer sessions. To determine whether the Microsoft MPIO iSCSI session limit might apply,
multiply the expected number of volumes by the number of storage systems plus the number of
server NICs.
NOTE: If the storage configuration is not recommended for HP DSM for MPIO, then uninstall the HP
DSM for MPIO during the upgrade to V9.x and use the Microsoft DSM.
Installing the HP DSM for MPIO
Supported versions of Microsoft Windows Server
The HP DSM for MPIO supports the following versions of Microsoft Windows Server.
•
Windows Server 2003, Windows Server 2003 with Service Pack 1
•
Windows Server 2003 SP1
•
Windows Server 2008, Windows Server 2008 with Service Pack 1, Windows Server 2008 with
Service Pack 2
•
Windows Server 2008 Server Core
•
Windows Server 2008 R2
•
Windows Server 2008 R2 Server Core
NOTE: To help avoid issues with active/passive MPIO configurations (both the HP DSM for MPIO
and Microsoft DSM) and disk timeout errors when the iSCSI initiator detect a failure and reconnects,
you may want to change the EnableNOPOut registry setting to 1 as described in the Microsoft iSCSI
Initiator Driver Timers section of the Microsoft iSCSI Software Initiator Version 2.X Users Guide.
Prerequisites
Windows Server 2003
4
•
32-bit or 64-bit version of Windows Server 2003
•
The latest Microsoft iSCSI Initiator
•
Microsoft DSM installed
Installing the HP DSM for MPIO
Windows Server 2008 and Server Core option
•
32-bit or 64-bit version of Windows Server 2008, the Server Core, Windows Server 2008 R2,
or R2 Server Core installations
•
The Microsoft iSCSI Initiator, which comes installed with all Windows Server 2008 and the Server
Core installation
•
The Microsoft Multipath IO optional component installed
If installing the HP DSM for MPIO into an existing Microsoft cluster
1.
2.
Move all cluster resources and related file shares to one system that will stay active.
Pause the system that holds no resources and install the HP DSM for MPIO.
Updating the HP DSM for MPIO
NOTE: The preferred update order is to update the HP DSM for MPIO first, then update the SAN/iQ
software.
Choose one of the following options:
•
•
If you are running a Version 7.x of the HP DSM for MPIO
◦
Uninstall the previous version of the HP DSM for MPIO.
◦
Reboot the server.
◦
Download and install the latest version of the MS iSCSI Initiator. You must select the Microsoft
MPIO Multipathing Support for iSCSI option when installing the Microsoft iSCSI Initiator.
◦
Install the Version 9.x HP DSM for MPIO.
If you are running Version 8.0 or 8.1 of the HP DSM for MPIO, use the Solution Pack for Microsoft
Windows DVD to upgrade to Version 9.0.
After upgrading to Version 9.0, use the new installer provided in the HP P4000 Application
Integration Solution Pack DVD.
To install the HP DSM for MPIO
IMPORTANT:
1.
2.
3.
4.
Installing the HP DSM for MPIO requires a server reboot to complete the installation.
Begin the installer one of the following ways:
•
Insert the HP P4000 Application Integration Solution Pack DVD in the DVD drive.
•
Double-click the executable that you downloaded to start the installation.
From the Home page of HP P4000 Application Integration Solution Pack installer, click DSM for
MPIO.
From the HP P4000 DSM for Microsoft MPIO page, click Install DSM for MPIO to begin the
installer.
Accept the terms of the license agreement and click Next.
The installation wizard takes you through the installation process for the HP DSM for MPIO.
5.
Reboot the server to complete the installation.
Perform a silent install for Windows Server 2008 Server Core option
1.
2.
Open a command prompt and use the cd command to navigate to setup.exe in the installation
media.
Type the following command:
setup /s /f1".\setup.iss"
Installing the HP DSM for MPIO
5
The setup begins. You will see nothing until after a minute or two, when the server reboots.
3.
When the server is back up, check \Windows\dsminstall.log for errors.
Connecting volumes with MPIO
Once the HP DSM for MPIO or Microsoft DSM is installed on the server, all iSCSI volume connections
made to an iSCSI SAN will attempt to connect with the DSM. You do not need to configure the multiple
I/O paths manually.
If you are also using the Multi-Site SAN features, you can assign servers to specific sites to avoid
high-latency connections between sites. For more information, see the HP P4000 Multi-Site HA/DR
Solution Pack User Guide.
Connecting application servers with single or multiple NICs to volumes
To connect to the volumes using the iSCSI Initiator:
1. Open the iSCSI Initiator.
2. On the Discovery tab, enter the VIP address of the cluster.
3. On the Targets tab, select the volume to log on to.
4. Click Log On.
5. Select the Enable multi-path check box.
Figure 1 Enabling multi-path for DSM
6.
7.
8.
6
[Optional] If you want this volume to be available after rebooting, select the Automatically restore...
check box.
Click Advanced to open the Advanced Settings window.
Configure the Advanced Settings as follows:
•
For Local adaptor, select Microsoft iSCSI initiator.
•
For Source IP, select the IP address of the storage NIC to connect to the volume.
•
For Target portal, select the VIP of the cluster containing the volume.
Connecting volumes with MPIO
Figure 2 Configuring advanced settings for multiple NICs
9. Click OK to close the Advanced Settings dialog.
10. Click OK again to finish logging on.
11. If you want to set the MPIO load balancing policy, see “Setting the Microsoft DSM MPIO load
balancing policy” (page 8).
12. If you have multiple NICs, repeat steps 3 through 11 for the additional storage NICs.
Connecting volumes in a Multi-Site SAN
Connecting to volumes in a Multi-Site SAN is similar to connecting to volumes in a single-site
configuration, with a couple of important differences.
•
For proper failover/failback configuration of a Multi-Site SAN you must configure all cluster VIPs
for discovery. List the VIPs in the preferred order of connection. For example, if Site A is the first
preference for connection, put the VIP associated to Site A first in the discovery list.
•
You must also log on to the volumes with the default Target Portal setting.
Using multiple cluster VIPs when connecting to a Multi-Site SAN
Use the Virtual IP address of the HP P4000 SAN Solution cluster when connecting to volumes using
MPIO. In a Multi-Site SAN, you must enter the VIPs of all the multi-site clusters on all the application
servers to take advantage of the DSM's multipath I/O capabilities. In addition, all the application
servers must have the VIPs listed in the same order.
A sample Multi-Site SAN configuration is shown. In this configuration, the cluster has three sites: Site
A, Site B, and Site C. Site A is primary.
Connecting volumes with MPIO
7
Figure 3 Multi-site SAN VIPs with MPIO
Setting the Microsoft DSM MPIO load balancing policy
When you connect application servers to volumes, you can also set the MPIO load balancing policy
in the iSCSI Initiator.
Supported load balancing options
Only two load balancing options are supported, Fail Over and Round Robin. For the Microsoft DSM
with Windows 2003 Server, only the Fail Over Only option is supported.
•
Fail Over Only – Also called active/passive MPIO. Two (or more) I/O paths are built between
the server and the storage. One path is actively used for I/O to the storage. The other paths are
available for failover only in the event the primary path goes down.
•
Round Robin – Also called active/active MPIO. Two (or more) I/O paths are built between the
server and the storage. All paths are actively used for I/O to the storage.
In the HP DSM for MPIO, Vendor Specific is selected by default. This option is the same as selecting
Fail Over Only and will not be available after you select another option. In the Microsoft DSM, Fail
Over Only is the default selection for all Windows versions, except for Windows 2008 R2, for which
Round Robin is the default.
The MPIO load balancing policy affects the number of iSCSI connections created to the volume. The
number of connections also differs based on whether you are using the HP DSM for MPIO or the
Microsoft DSM. “HP DSM for MPIO with two NICs in the server and Failover MPIO load balancing”
(page 8) through “Microsoft DSM with two NICs in the server and Round Robin MPIO load balancing”
(page 9) show the connections created with applications servers that have two NICs.
Figure 4 HP DSM for MPIO with two NICs in the server and Failover MPIO load balancing
8
Connecting volumes with MPIO
Figure 5 HP DSM for MPIO with two NICs in the server and Round Robin MPIO load balancing
Figure 6 Microsoft DSM with two NICs in the server and Fail Over MPIO load balancing
Figure 7 Microsoft DSM with two NICs in the server and Round Robin MPIO load balancing
NOTE: Be sure to follow the steps below to set the MPIO load balancing policy. Similar options are
available for Multiple Connected Session (Windows 2008) or Session Connections (Windows 2003).
These session load balancing policies will have no effect.
To set the MPIO load balancing policy:
1. Select the target you just logged on to and click Details.
2. Select the Devices tab.
3. Click Advanced.
This step is not needed for Windows 2008 Server R2.
Connecting volumes with MPIO
9
4.
Click the MPIO button or tab.
If the MPIO button or tab is not available, MPIO is not installed and enabled.
5.
6.
7.
From the Load balancing policy drop-down list, select either Fail Over Only or Round Robin.
Click OK.
Click OK.
Troubleshooting MPIO
Verifying HP DSM for MPIO operations
After logging on to a volume via iSCSI, the HP DSM for MPIO automatically builds a data path to
each storage system in the cluster and one administrative path. You can verify the HP DSM for MPIO
operations by looking at the Details window of the iSCSI connection for the volume after logging on
to that volume.
Figure 8 Verifying the HP DSM for MPIO connections
What happens if a path fails with the HP DSM for MPIO
If one I/O path fails, volume I/O continues because additional active I/O paths to the iSCSI SAN
remain, as illustrated in Figure 9 (page 11).
10
Troubleshooting MPIO
Figure 9 Multiple paths ensure continued I/O in event of path failure
When the problem with the I/O path is repaired, the HP DSM for MPIO reconnects an I/O path to
the storage system, thus restoring optimized performance and fault tolerance.
Verifying Microsoft DSM operations
If you see two devices that are exactly the same listed in the Disk Manager or My Computer, you may
not have MPIO installed or you may not have logged using MPIO. For more information, see “Using
Microsoft DSM” (page 3) and “Connecting volumes with MPIO” (page 6).
Trouble bringing disks online
If you cannot access volumes or do not see the disks (in Disk Manager or My Computer), you may
need to bring the disks online. You may also see that the device in the iSCSI Initiator is listed with a
device number —1 or with no device name. Use the following Windows utilities to solve the problem:
•
The automount setting in the Windows 2008 and Windows 2008 R2 DiskPart Command-Line
affects whether disks will mount after changes in MPIO status, such as uninstalling generic MPIO
or the HP DSM for MPIO.
To run DiskPart, open a Windows command line and run diskpart.exe.
For detailed information about the DiskPart Command-Line, see http://technet.microsoft.com/
en-us/library/cc766465(WS.10).aspx.
•
Log off all iSCSI sessions and use the command automount scrub to clean up volume mount
point directories and registry settings for volumes that are no longer in the system. This can clean
up conflicting disk information that prevents disks from coming online. Information about automount
is available by typing the command help automount from the diskpart command line.
•
Check the SAN policy setting. The SAN policy should be set to Online All for SAN/iQ volumes
to remount after uninstalling the HP DSM for MPIO. Information about the SAN policy is available
by typing the command help SAN from the diskpart command line.
Uninstalling the HP DSM for MPIO
IMPORTANT:
1.
2.
3.
4.
Uninstalling the HP DSM for MPIO requires a reboot of the system.
Log off all iSCSI sessions.
Navigate to Control Panel and select Add or Remove Programs or Programs and Features,
depending on which version of Windows you are running.
Remove the HP DSM for MPIO.
Reboot the system.
Uninstalling the HP DSM for MPIO
11
Performing a silent uninstall for the Windows 2008 Server Core option
IMPORTANT:
1.
2.
Uninstalling the HP DSM for MPIO requires a reboot of the system.
Open a command prompt and use the cd command to navigate to setup.exe in the installation
media.
Type the following command:
setup /removeonly /s /f1”.\uninst.iss”
3.
4.
12
The uninstall begins. You will see nothing until after a minute or two, when the server reboots.
When the server is back up, check \Windows\dsminstall.log for errors.
Uninstalling the HP DSM for MPIO
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