Front cover
DB2 Virtualization
Learn setting up and configuring DB2
on PowerVM, VMware, and Hyper-V
Leverage virtualization
technologies
See best practices
Whei-Jen Chen
Jason Chan
Olaf Mueller
Malcolm Singh
Tapio Väättänen
ibm.com/redbooks
International Technical Support Organization
DB2 Virtualization
September 2009
SG24-7805-00
Note: Before using this information and the product it supports, read the information in
“Notices” on page vii.
First Edition (September 2009)
This edition applies to DB2 for Linux, UNIX, and Windows Version 9.1 or later, PowerVM,
POWER5, POWER6, VMware Virtual Infrastructure 3 or later, vSphere 4 or later, and Microsoft
Windows Server 2008 SP2 with Hyper-V RTM (Update KB950050).
© Copyright International Business Machines Corporation 2009. All rights reserved.
Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP
Schedule Contract with IBM Corp.
Contents
Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
The team who wrote this book . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x
Acknowledgement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Become a published author . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Comments welcome. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii
Chapter 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1.1 What is virtualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1.2 History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1.3 Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Terminology and definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2.1 Virtual server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.2 Virtual machine monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.3 Machine-based virtualization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.2.4 Operating-system-based virtualization . . . . . . . . . . . . . . . . . . . . . . . 11
Chapter 2. Virtualization technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.1 DB2 support for virtualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.1.1 Support matrix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.1.2 Features and functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.1.3 Licensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.2 PowerVM on Power Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.3 VMware vSphere. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.3.1 vCenter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
2.3.2 VMotion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
2.3.3 Distributed Resource Scheduler . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.4 Hyper-V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.5 Linux Kernel-based Virtual Machine (KVM) . . . . . . . . . . . . . . . . . . . . . . . 39
2.6 z/VM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.7 Xen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
2.8 Parallels Virtuozzo Containers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
2.9 Solaris Zones (containers) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
2.10 HP Integrity VM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Chapter 3. Power Systems and PowerVM . . . . . . . . . . . . . . . . . . . . . . . . . . 47
© Copyright IBM Corp. 2009. All rights reserved.
iii
3.1 Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.1.1 POWER Hypervisor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.1.2 Hardware Management Console . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.1.3 Integrated Virtualization Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.1.4 Logical partition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.1.5 Dynamic logical partitioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.1.6 Virtual I/O Server. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.1.7 Live Partition Mobility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
3.1.8 Workload partition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
3.1.9 Overall architectural picture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
3.2 Power Systems and PowerVM setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
3.3 DB2 setup and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
3.3.1 Installing and setting up DB2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
3.3.2 Configuration example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
3.4 Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Chapter 4. VMware vSphere . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
4.1 Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
4.1.1 vSphere. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
4.1.2 ESX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
4.1.3 VMFS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
4.1.4 vCenter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
4.1.5 VMware High Availability (HA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
4.1.6 VMware Fault Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
4.1.7 Distributed Resource Scheduler . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
4.1.8 VMotion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
4.2 VMware setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
4.3 Virtual machine setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
4.3.1 Creating virtual machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
4.3.2 Setting up operating system environment . . . . . . . . . . . . . . . . . . . . . 97
4.3.3 Resource settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
4.3.4 Monitoring the resource usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
4.3.5 Cloning and templates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
4.4 DB2 setup and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
4.4.1 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
4.4.2 Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
4.5 Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Chapter 5. Hyper-V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
5.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
5.1.1 Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
5.1.2 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
5.2 Installation and setup of Hyper-V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
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DB2 Virtualization
5.2.1 Adding the Hyper-V role in Windows Server 2008 . . . . . . . . . . . . . 112
5.2.2 Network configuration for Hyper-V . . . . . . . . . . . . . . . . . . . . . . . . . 114
5.2.3 Disk configuration for Hyper-V . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
5.3 Creation and setup of virtual machines on Hyper-V . . . . . . . . . . . . . . . . 116
5.3.1 Creating a virtual machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
5.3.2 Additional configuration of the virtual machine . . . . . . . . . . . . . . . . 118
5.4 DB2 in Hyper-V environments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
5.4.1 Supported OS platforms for DB2 on Hyper-V . . . . . . . . . . . . . . . . . 122
5.4.2 Installation of operating system and DB2 . . . . . . . . . . . . . . . . . . . . 122
5.4.3 Configuration of DB2 in Hyper-V environments . . . . . . . . . . . . . . . 123
5.5 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Appendix A. Extension of virtualization technologies . . . . . . . . . . . . . . 125
Virtual appliances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Installation and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Development and deployment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
DB2 virtual appliances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
Extensions of DB2 virtual appliances . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
Cloud computing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
Cloud computing and DB2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Related publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
IBM Redbooks publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Other publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Online resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
How to get Redbooks publication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Help from IBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Contents
v
vi
DB2 Virtualization
Notices
This information was developed for products and services offered in the U.S.A.
IBM may not offer the products, services, or features discussed in this document in other countries. Consult
your local IBM representative for information on the products and services currently available in your area.
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product, program, or service may be used. Any functionally equivalent product, program, or service that
does not infringe any IBM intellectual property right may be used instead. However, it is the user's
responsibility to evaluate and verify the operation of any non-IBM product, program, or service.
IBM may have patents or pending patent applications covering subject matter described in this document.
The furnishing of this document does not give you any license to these patents. You can send license
inquiries, in writing, to:
IBM Director of Licensing, IBM Corporation, North Castle Drive, Armonk, NY 10504-1785 U.S.A.
The following paragraph does not apply to the United Kingdom or any other country where such
provisions are inconsistent with local law: INTERNATIONAL BUSINESS MACHINES CORPORATION
PROVIDES THIS PUBLICATION "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR
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This information could include technical inaccuracies or typographical errors. Changes are periodically made
to the information herein; these changes will be incorporated in new editions of the publication. IBM may
make improvements and/or changes in the product(s) and/or the program(s) described in this publication at
any time without notice.
Any references in this information to non-IBM Web sites are provided for convenience only and do not in any
manner serve as an endorsement of those Web sites. The materials at those Web sites are not part of the
materials for this IBM product and use of those Web sites is at your own risk.
IBM may use or distribute any of the information you supply in any way it believes appropriate without
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Information concerning non-IBM products was obtained from the suppliers of those products, their published
announcements or other publicly available sources. IBM has not tested those products and cannot confirm
the accuracy of performance, compatibility or any other claims related to non-IBM products. Questions on
the capabilities of non-IBM products should be addressed to the suppliers of those products.
This information contains examples of data and reports used in daily business operations. To illustrate them
as completely as possible, the examples include the names of individuals, companies, brands, and products.
All of these names are fictitious and any similarity to the names and addresses used by an actual business
enterprise is entirely coincidental.
COPYRIGHT LICENSE:
This information contains sample application programs in source language, which illustrate programming
techniques on various operating platforms. You may copy, modify, and distribute these sample programs in
any form without payment to IBM, for the purposes of developing, using, marketing or distributing application
programs conforming to the application programming interface for the operating platform for which the
sample programs are written. These examples have not been thoroughly tested under all conditions. IBM,
therefore, cannot guarantee or imply reliability, serviceability, or function of these programs.
© Copyright IBM Corp. 2009. All rights reserved.
vii
Trademarks
IBM, the IBM logo, and ibm.com are trademarks or registered trademarks of International Business
Machines Corporation in the United States, other countries, or both. These and other IBM trademarked
terms are marked on their first occurrence in this information with the appropriate symbol (® or ™),
indicating US registered or common law trademarks owned by IBM at the time this information was
published. Such trademarks may also be registered or common law trademarks in other countries. A current
list of IBM trademarks is available on the Web at http://www.ibm.com/legal/copytrade.shtml
The following terms are trademarks of the International Business Machines Corporation in the United States,
other countries, or both:
AIX®
DB2®
IBM®
Optim™
POWER Hypervisor™
Power Systems™
POWER5™
POWER6®
PowerVM™
POWER®
Redbooks®
Redbooks (logo)
System z®
z/VM®
®
The following terms are trademarks of other companies:
VMotion, VMware, the VMware "boxes" logo and design are registered trademarks or trademarks of
VMware, Inc. in the United States and/or other jurisdictions.
AMD, AMD-V, the AMD Arrow logo, and combinations thereof, are trademarks of Advanced Micro Devices,
Inc.
SUSE, the Novell logo, and the N logo are registered trademarks of Novell, Inc. in the United States and
other countries.
Oracle, JD Edwards, PeopleSoft, Siebel, and TopLink are registered trademarks of Oracle Corporation
and/or its affiliates.
Red Hat, and the Shadowman logo are trademarks or registered trademarks of Red Hat, Inc. in the U.S. and
other countries.
Solaris, and all Java-based trademarks are trademarks of Sun Microsystems, Inc. in the United States, other
countries, or both.
Hyper-V, Microsoft, MS, SQL Server, Windows Server, Windows, and the Windows logo are trademarks of
Microsoft Corporation in the United States, other countries, or both.
Intel, Itanium-based, Intel logo, Intel Inside logo, and Intel Centrino logo are trademarks or registered
trademarks of Intel Corporation or its subsidiaries in the United States, other countries, or both.
UNIX is a registered trademark of The Open Group in the United States and other countries.
Linux is a trademark of Linus Torvalds in the United States, other countries, or both.
Other company, product, or service names may be trademarks or service marks of others.
viii
DB2 Virtualization
Preface
Server virtualization technologies are becoming more popular to help efficiently
utilize resources by consolidating servers. IBM®, the first company that
developed and made available the virtual technology in 1966, offers advanced,
powerful, reliable, and cost-saving virtualization technologies in various hardware
and software products including DB2® for Linux, UNIX, and Windows. This IBM
Redbooks® publication describes using IBM DB2 9 with server virtualization.
We start with a general overview of virtualization and describe specific server
virtualization technologies to highlight how the server virtualization technologies
have been implemented. With this introduction anyone new to virtualization will
have a better understanding of server virtualization and the industry server
virtualization technologies available in the market.
Following the virtualization concept, we describe in detail the setup,
configuration, and managing of DB2 with three leading server virtualization
technologies:
 IBM Power Systems™ with PowerVM™
 VMware
 Hyper-V
We discuss the virtual machine setup with DB2 in mind to help IT support
understand the effective ways of setting up a virtual environment specific for
DB2. We explain the architecture and components of these three server
virtualization technologies to allow DBAs to understand how a database
environment using DB2 can benefit from using the server virtualization
technologies.
In addition, we discuss the DB2 features and functions that can take advantage
of using server virtualization. These features are put into practice when
describing how to set up DB2 with the three virtualization technologies discussed
in this book. This book also includes a list of best practices from the various tests
performed while using these virtualization technologies. These best practices
can be used as a guideline or a reference when setting up DB2 using these
virtualization technologies.
© Copyright IBM Corp. 2009. All rights reserved.
ix
The team who wrote this book
This book was produced by a team of specialists from around the world working
at the International Technical Support Organization, San Jose Center.
Whei-Jen Chen is a Project Leader at the International Technical Support
Organization, San Jose Center. She has extensive experience in application
development, database design and modeling, and DB2 system administration.
Whei-Jen is an IBM Certified Solutions Expert in Database Administration and
Application Development, as well as an IBM Certified IT Specialist.
Jason Chan is the Linux and Virtualization Lead of the Data
Management Emerging Partnerships and Technologies team. He
joined IBM as a full-time employee in 2003 and has specialized in
various projects dealing with Linux and virtualization with DB2 and
other data management products. He frequently engages various
Linux, virtualization, and hardware partners to bring to the forefront
new technologies for use with DB2, as well as participating in the
team's mandate of enabling IBM Business Partners on DB2 through the many
DB2 bootcamps around the world. Jason is based at the IBM Canada Lab in
Toronto and holds a Bachelor of Applied Science degree in Computer
Engineering from the University of Toronto.
Olaf Mueller is a DB2 and Optim™ Consultant in Germany. He has
20 years of experience in the database field. He holds a pre-degree
in chemistry from the Johannes-Gutenberg Universitaet in
Mainz/Germany. His areas of expertise include skills in DB2 LUW,
Oracle, and Optim, as well as strong migration skills to DB2 LUW.
Malcolm Singh is a Software Development Analyst at the IBM
Canada Lab - Toronto Site (formerly the IBM Toronto Lab). He works
in the Information Management division within the IBM Software
Group. Malcolm started his career at IBM as an intern working on
DB2 for Linux, UNIX, and Windows (DB2 LUW). He continues to
work with DB2 LUW and has an extensive knowledge of both DB2
LUW and Database Theory. His current focus is on the DB2 engine, which
includes the DB2 Kernel, Recovery, and Optimizer components.
Tapio Väättänen is an Advisory IT Specialist with IBM Global
Technology Services in Finland. He has more than 15 years of
experience in the IT industry and extensive experience in the area
of database and UNIX server administration. Tapio is an IBM
Certified DB2 Administrator and VMware Certified Professional as
well as the Open GROUP Certified IT Specialist. Tapio is currently
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DB2 Virtualization
working on the Finnish DB2 team, providing consultation services and supporting
DB2 customers focusing on high availability, performance tuning, and disaster
recovery solutions.
Acknowledgement
Thanks to the following people for their contributions to this project:
Boris Bialek
Andre Albuquerque
Piotr Pruski
Anoop Sood
Melody Ng
Peter Kokosielis
IBM Toronto Laboratory, Canada
Pauli Rämö
Pekka Siekkinen
IBM Finland
Pentti Karikko
Isoworks, Finland
Toni Einola
DataInfo Helsinki, Finland
Emma Jacob
International Technical Support Organization, San Jose Center
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Preface
xi
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xii
DB2 Virtualization
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Chapter 1.
Introduction
Server virtualization is widely implemented to increase server resource utilization
by consolidating servers. In this chapter we provide a general overview of
virtualization and then describe server virtualization in more detail. The
explanation is at a level of understanding for anyone new to the topic of
virtualization as well as for those who must reacquaint themselves with server
virtualization terminology. Along with this, we briefly discuss the benefits of
virtualization. Also, we include a brief history of server virtualization to explain
how this technology was first developed.
© Copyright IBM Corp. 2009. All rights reserved.
1
1.1 Overview
Virtualization is becoming more popular due to its increasing ease to efficiently
utilize resources. Even though IBM has been using virtualization since the 1960s,
there is a rapid growth for virtualization on UNIX and x86 platforms. This growth
in virtualization is first evident with server consolidation in data centers, but it also
improves business flexibility to meet company needs on demand.
Server virtualization technologies are becoming more mainstream to help
efficiently utilize resources by consolidating servers. A consolidated server can
host more than one virtual machine by sharing hardware resources. The virtual
machines themselves are provided to users as an isolated working environment.
In fact, these working environments could easily be perceived as being hosted by
a separate stand-alone server and not from a virtual environment created by a
virtual machine.
1.1.1 What is virtualization
Virtualization is, from a computer science and engineering perspective, the
abstraction of a physical computing environment using generated virtual
resources to create a logical simulated environment.
There are many types of virtualization, but they all do one of two things:
 Create a smaller working environment.
 Create a larger working environment.
Multiple working environments created from a single physical computing
environment result in a smaller but similar working environment, whereas a
larger working environment is built upon many physical computing environments
to create one working environment. So virtualization, in a general sense, either
creates a smaller or larger working environment that is similar to the underlying
hardware.
The most recognizable virtualization that everyone can relate to is the
partitioning of a hard disk drive (HDD). In a personal computer (PC) environment,
a large HDD is usually divided into smaller partitions. Each partition is then
identified as a separate disk drive to the system user. But in reality each separate
disk drive is from the same HDD with the same underlying characteristics. In this
case, smaller logical working environments are created from one physical
environment similar to the underlying hardware.
In the other case, a set of HDDs can be combined to create one larger storage
space. This larger storage space is viewed as one homogeneous disk to the
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DB2 Virtualization
system user, which is commonly referred to as a logical volume group (LVG).
The LVG comprises the HDDs with the same underlying characteristics, so a
larger logical working environment is built from more than one physical
environment that is similar to the underlying hardware.
There are many types of virtualization being used today. The most common
types of virtualization are:
 Server virtualization
Server virtualization creates multiple virtual servers within a single physical
server. These virtual servers are independent working environments that use
virtual resources, where the virtual resources are an abstraction of the
underlying hardware from the physical server. As a result, the virtual
resources share the same characteristics as underlying hardware. So the
virtual server is exactly like the physical server, only smaller in capacity.
The types of virtual resources that are used by the virtual server include CPU
and memory, which can be shared or dedicated resources among the virtual
servers hosted on a single physical server.
For instance, two enterprise servers each have two 4-core CPUs. These two
enterprise servers are both under utilized. If the capacity allows, you can have
two virtual servers on one enterprise server sharing the two CPUs. You also
can dedicate one CPU to each virtual server. This consolidation frees you one
enterprise server for other applications and maximizes physical resource
usage while maintaining capacity.
This virtualization is the primary focus of this book and is discussed in more
detail in the remaining chapters.
 Storage virtualization
Storage virtualization used in enterprise environments is essentially the
amalgamation of physical storage. Multiple physical storage devices are
combined into a single logical resource. This single logical resource appears
as a single storage device to the system user. The use of logical resources
creates an abstraction by hiding the complexities of the physical storage
devices. This abstraction improves the management and administration of the
storage devices.
 Network virtualization
Network virtualization usually involves the splitting of available bandwidth into
separate smaller channels. The smaller channels allow the network to be
shared among different devices, which include servers and storage arrays.
However, even though the bandwidth is shared, the separate channels can be
isolated from each other. This helps improve the network resource utilization
and the management of the network infrastructure.
Chapter 1. Introduction
3
1.1.2 History
While server virtualization is becoming more popular, it is based on a technology
developed in the late 1960s. This technology was developed and made available
by IBM when it shipped the System/360 Model 67 mainframe in 1966. This was
achievable by using the CP-67/CMS, which was the successor to the
experimental prototype CP-40. The CP-67/CMS was the Virtual Machine Monitor
(VMM) that virtualized all of the hardware interfaces on the mainframe.
However, at that time the CP/CMS was only available in source code form
without any support. Full support for this ground-breaking virtualization
technology commenced in 1972. This occurred after the CP/CMS was
reimplemented for the System/370 mainframe as the VM/370. It was also at this
time that the term hypervisor was coined for this new technology. (This was in
relation to when the mainframe operating system was referred to as the
supervisor.)
1.1.3 Benefits
Server virtualization provides numerous benefits by consolidating many physical
server environments into fewer servers by sharing resources. This allows one
physical server to function as multiple virtual servers. The consolidation of
working environments helps simplify the overall infrastructure, lower the total cost
of ownership (TCO), and address environmental issues. Along with this, server
virtualization aids in improving responsiveness and business resiliency.
Infrastructure simplification
The consolidation of servers takes the use of multiple servers by reducing them
into fewer servers. This allows one server to host many once-dedicated servers
that would be under utilized on separate physical servers. Server consolidation:
 Reduces server sprawl
 Increases physical server utilization
 Improves infrastructure manageability
Total cost of ownership
The use of fewer servers to deliver and meet business needs reduces the overall
total cost of ownership. This produces an increase in the return of investment
(ROI) when using virtualization. This is achieved by:
 Increasing server utilization
 Decreasing management infrastructure costs
 Lowering the cost to deploy new environments
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DB2 Virtualization
Environmental issues
The current focus on using energy resources more efficiently can be aided with
using virtualization. This is primarily achieved by reducing the number of physical
servers. With fewer servers needed, the following environmental concerns are
addressed:
 Reduce electrical energy consumption.
 Decrease cooling resources.
 Decrease physical space.
Improved responsiveness
The use of virtualization allows resources to be shared among the virtual
servers. Shared resources can be re-allocated as needed to maintain capacity
needs for expected and unexpected workloads. Using shared resources can
effectively:
 Dynamically respond to application workloads.
 React to changing business needs and cycles.
 Improve overall resource manageability.
Business resiliency
Virtualization can aid in creating a resilient and highly available (HA)
infrastructure. This type of infrastructure lessens the impact of planned and
unplanned outages, which can include a full disaster recovery. So this
virtualization can help:
 Increase the availability for application software.
 Insulate users from system failures.
 Manage high availability (HA) environments with less cost.
1.2 Terminology and definitions
Server virtualization is described as an abstraction of physical hardware
resources to create virtual working environments. The virtual working
environments are created by using virtual resources to make virtual servers. As a
result of using virtual resources, multiple virtual servers can be hosted on one
physical server, which is based on capacity requirements, while the virtual
servers are managed and controlled by a virtual machine monitor (VMM).
However, server virtualization is implemented using different techniques:




Full virtualization
Paravirtualization
Hardware-assisted virtualization
Operating system (OS)-based virtualization
Chapter 1. Introduction
5
The first three types of virtualization are considered to be types of
machine-based virtualization, which is different from OS-based virtualization,
which is based on where the virtual machine monitor is located. But all types of
server virtualizations use virtual servers and virtual machine monitors.
1.2.1 Virtual server
The virtual server is also commonly referred to as the virtual machine (VM). The
virtual machine is the working environment created from virtual resources. These
virtual resources include CPU, RAM, hard drives, and other I/O interfaces. The
encapsulation of the virtual resources creates an isolated but compatible
environment similar to the underlying hardware. This allows the VM to run its own
operating system, which is referred to as the guest OS. So the VM seems like a
physical server to the system users.
1.2.2 Virtual machine monitor
The governing of the virtual machines on the physical server is handled by the
VMM. The virtual machine monitor is also known as the hypervisor. The
hypervisor controls the resources between the physical hardware and the virtual
machine. With this control the hypervisor also manages each guest OS used by
each virtual machine. This allows each guest OS to run concurrently in isolation
from each other. Depending on the hypervisor implementation, the guest OS can
be different among the virtual machines.
The hypervisor is an additional layer within the software stack, which is different
when comparing a virtualized server to a non-virtualized server. In a
non-virtualized server there is only the hardware, operating system, and software
applications, as illustrated in Figure 1-1.
Figure 1-1 Non-virtualized server
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DB2 Virtualization
The hypervisors used in server virtualization are classified as either type 1 or
type 2:
 Type 1
This type of hypervisor runs directly on top of the host hardware. This
provides a higher level of virtualization and security since the hypervisor
controls the hardware. Using this model, the guest OS is on the second layer
above the hardware, as illustrated in Figure 1-2. This hypervisor is also
referred to as bare-metal or native.
Figure 1-2 Type 1 hypervisor
Chapter 1. Introduction
7
 Type 2
This type of hypervisor runs on top of an existing operating system. This
provides wider support of hardware resources since the operating system
manages the resources. Using this model, the guest OS is on the third layer
above the hardware, as illustrated in Figure 1-3. This type of hypervisor is
also referred to as hosted.
Figure 1-3 Type 2 hypervisor
1.2.3 Machine-based virtualization
There are three types of machine-based virtulization:
 Full virtualization
 Paravirtualization
 Hardware-assisted virtualization
With machine-based virtualization, the hypervisor is placed directly on top of the
hardware. This allows the hypervisor to control the hardware while managing the
virtual machines. Depending on the hypervisor, different operating systems or
the same operating system at different levels can be used within each separate
virtual machine. But the key difference between these three types of
virtualizations is how privileged-mode or kernel-mode calls are handled and
executed on the CPU, whereas user-mode calls always run directly against the
CPU.
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DB2 Virtualization
Full virtualization
In a full virtualized environment the hypervisor must intercept privileged
instructions from the guest OS. The privileged instruction then must be simulated
by the hypervisor to fulfill the request on the hardware. This is illustrated in
Figure 1-4. Using this implementation, the guest OS does not need to be
modified. However, trapping instructions inside the hypervisor takes longer to
execute than if running the same privileged instructions directly on the CPU.
Therefore, full virtualization causes performance to greatly decrease in
comparison to physical implementations.
Figure 1-4 Full virtualization
Chapter 1. Introduction
9
Paravirtualization
Unlike full virtualization, paravirtualization allows privileged instructions to be run
directly against the CPU. This means that the hypervisor does not need to
intercept the privileged instruction for simulation. This is illustrated in Figure 1-5.
However, this can only be achieved if the guest OS is modified to cooperate with
the hypervisor. The guest operating system must be ported with the hypervisor
API, which might not be adapted by all operating systems.
Figure 1-5 Paravirtualization
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DB2 Virtualization
Hardware-assisted virtualization
The benefits of full virtualization and paravirtualization are combined with
hardware-assisted virtualization. This is where the guest OS can directly execute
privileged instructions on the CPU without being modified. Figure 1-6 illustrates
this. However, the CPU must be able to handle the privileged-mode or
kernel-mode calls by using virtualization extensions. This allows the trapping
instruction to be handled at the hardware layer rather than at the software layer.
Figure 1-6 Hardware-assisted virtualiztion
1.2.4 Operating-system-based virtualization
This type of server virtualization is commonly referred to as OS-level
virtualization. Operating-system-level virtualization uses a different technique
from machine-based virtualiztion to isolate the virtual machines, which are also
referred to as virtual instances. Instead of using a separate hypervisor on top of
the hardware, the hypervisor is built into the operating system. This requires the
operating system kernel to be modified. Therefore, there is no separate
hypervisor level since the hypervisor is at the operating system level, as
illustrated in Figure 1-7 on page 12. The main advantage is that since there is no
separate hypervisor level native performance is maintained. However, each
instance is tied to the main host operating system, so different levels of the
operating system cannot be used, nor can different OS be used.
Chapter 1. Introduction
11
Figure 1-7 OS-level virtualizaion
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DB2 Virtualization
2
Chapter 2.
Virtualization technologies
This chapter provides an high-level introduction to various virtualization
technologies and products currently available in the market. We focus on those
supported by DB2 for Linux, UNIX, and Windows Version 9 (DB2 9) and later.
First we describe the DB2 9 built-in support for virtualization, followed by the
supported virtualization technologies. The order of the solutions discussed is
random. There is no rank implication. In the subsequent chapters we provide
detail discussions about a number of virtualization solutions.
© Copyright IBM Corp. 2009. All rights reserved.
13
2.1 DB2 support for virtualization
In this section we first introduce the virtualization environments supported by
DB2 9. Then we describe the DB2 9 built-in features and functions that enable
DB2 9 to run very well in different virtualization environments. Finally, we discuss
the DB2 9 licensing model as it relates to virtualization.
2.1.1 Support matrix
DB2 9 provides support for many virtualization environments. For the most
up-to-date list of the supported environments, refer to:
http://www.ibm.com/developerworks/wikis/display/im/DB2%20Virtualization%20Support
That Web site also contains information about the restrictions of the supported
environments. Table 2-1 to Table 2-4 on page 15 show the virtual environments
supported by DB2 9 and what versions of DB2 9 support these architectures.
Table 2-1 Full virtualization environments for x86 and x64 architectures
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Hypervisor
Architecture
Minimum
guest OS
(Windows)
Minimum
guest OS
(Linux)
Minimum DB2
level
VMware ESX
3.0.1 and later
VMware
vSphere 4
x86/x64
System listed
on ESX HCL
Any Microsoft
Windows level
supported by
both DB2 and
ESX
Any Linux
distribution
supported by
both DB2 and
ESX
DB2 9.1
DB2 9.5
DB2 9.7
Red Hat
Enterprise
Linux
(RHEL) 5.2
and later
Xen HVM
x64 System
with INTEL-VT
or AMD-V
Not supported
RHEL 5.2
64 bit
DB2 9 FP4
DB2 9.5 FP1
DB2 9.7
SUSE Linux
Enterprise
Server
(SLES) 10
SP2 and later
Xen HVM
x64 System
with INTEL-VT
or AMD-V
Not supported
SLES 10 SP2
64 bit
DB2 9 FP4
DB2 9.5 FP1
DB2 9.7
Microsoft
Windows 2008
SP2
Hyper-V
x64 System
with INTEL-VT
or AMD-V
Windows 2008
Server SP2
Not supported
DB2 9.5 FP4
DB2 9.7
DB2 Virtualization
Table 2-2 OS virtualization environments for x86 and x64 architectures
Technology
Architecture
Operating system
Minimum DB2
level
Solaris Zones
x64
Solaris 10
DB2 9 FP4
DB2 9.5 FP1
DB2 9.7
Parallels Virtuozzo
Containers
x64
Windows 2003
SLES 10
DB2 9.1
DB2 9.5
Table 2-3 Full virtualization environments for non-x86 platforms
Hypervisor
Architecture
Minimum guest
OS
Minimum DB2
level
PowerVM
IBM Power Systems
AIX® 5.3 TL05
AIX 6.1
RHEL 5
SLES 10 SP1
DB2 9.1
DB2 9.5
DB2 9.7
z/VM® 5.2
z/VM 5.3
IBM System z®
SLES 9 SP3
SLES 10 SP1
RHEL 4 U4
RHEL 5 (64-bit
only)
DB2 9.1
DB2 9.5
DB2 9.7
HP-UX Virtual
Partitions (vPars)
HP Integrity Servers
HP-UX 11i v3
DB2 9 FP5
DB2 9.5 FP2
DB2 9.7
Table 2-4 OS virtualization environments for non-x86 platforms
Technology
Operating system
Minimum DB2 level
AIX System Workload
Partitions (WPARS)
AIX 6.1
DB2 9 FP4
DB2 9.5
DB2 9.7
Solaris Zones
Solaris 10
DB2 9.1
DB2 9.5
DB2 9.7
2.1.2 Features and functions
DB2 9 contains several features and functions that are not built in particular for
virtualized environments but that are very beneficial in those environments. In
Chapter 2. Virtualization technologies
15
this section we focus on the built-in autonomic features and the various data
compression features enabled.
The DB2 built-in autonomic features significantly reduce the amount of time that
a DBA must spend on keeping up a database. This is very important, as the
number of databases keeps increasing in this information explosion era. The
autonomic features help increase DBA’s productivity and reduce a company’s
total cost.
I/O throughput is a major concern with all databases, especially in virtualized
environments where several virtual machines share the same physical I/O
interface. The DB2 compression features help to increase the I/O throughput
significantly. This capability makes them a perfect feature for virtualized
environments.
Autonomic features
In today’s business environment, database vendors face many challenges and
business requirements. Some of these are:
 Databases are getting larger and more complicated.
 Return on investment.
 DBA skills: For example, are all DBAs as highly qualified as necessary and do
they have time to enhance or obtain their skills?
 Efficient use of manpower: Highly skilled DBAs should spend less time in
routine maintenance tasks.
 Maintenance windows are becoming smaller and less frequent.
All of these topics are related to one another. They all can be alleviated with
DB2 9 autonomic features.
When looking at built-in autonomic features in DB2 9, there are four major areas
to discuss:




16
Self-configuration
Self-healing
Self-managing
Self-optimization
DB2 Virtualization
These areas are depicted in Figure 2-1.
Figure 2-1 Autonomic computing areas
Self-configuration
Self-configuration of DB2 starts at the creation of a database. If you create a DB2
database the so-called Configuration Advisor (CA) is started automatically in the
background to collect the environment characteristics of your system. Based on
the collected information, several instance and database parameters, including
buffer pools, are adjusted to make your database run well in your environment
from the beginning. You also can provide additional information to the CA such
as number of concurrent applications, number of statements per transaction,
workload type, and so on.
Chapter 2. Virtualization technologies
17
Combined with a mathematical model of each configuration parameter, based on
expert heuristics, the CA calculates optimal values for several parameters and
buffer pools. Figure 2-2 shows this process.
Figure 2-2 Self-configuration
For more detailed information about CA refer to:
http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.db2.luw.admin
.dbobj.doc/doc/c0052481.html
Self-healing
The built-in DB2 9 Health Monitor checks the healthiness of all active database
objects as frequently as deemed necessary. It is able to generate alerts based on
whether a health indicator exceeds a threshold or is in a non-normal state. In
case of an alert, it sends notifications to the DB2 administration notification log
and e-mails or pages the contacts on the notification list. The DB2 9 Health
Monitor also advises about the severity of an alert. You can define corrective
actions (scripts or tasks) for health alerts to be executed automatically. You can
use both the DB2 command line and the Health Center GUI to administrate the
Health Monitor. The Health Center allows you to define the corrective actions,
health indicator settings, and many other features.
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DB2 Virtualization
Figure 2-3 illustrates the health checking algorithm.
Figure 2-3 Self-healing algorithm
For more detailed information see:
http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.db2.luw.admin
.mon.doc/doc/c0011709.html
Note that the DB2 9 Health Monitor and Health Center are deprecated in DB2
9.7. New tools are available with the IBM Optim solutions. This tool suite replaces
the old tools that came with DB2. You can find more detailed information at:
http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.db2.luw.idm.
tools.doc/doc/c0055013.html
Chapter 2. Virtualization technologies
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Self-managing
The self-managing capabilities include automatic object maintenance and
automatic storage management:
 Automatic object maintenance
The automatic object maintenance self-managing features are enabled and
disabled through the database configuration parameters. There is a hierarchy
between these parameters, as shown in Example 2-1.
Example 2-1 Automatic maintenance parameters
AUTO_MAINT (ON
AUTO_DB_BACKUP (OFF)
AUTO_TBL_MAINT (ON)
AUTO_RUNSTATS (ON)
AUTO_STMT_STATS (OFF)
AUTO_STATS_PROF (OFF)
AUTO_PROF_UPD (OFF)
AUTO_REORG (OFF)
AUTO_MAINT is the master on/off switch. Individual child parameters can be
set to ON/OFF and the settings are persisted in the database configuration
file. These automatic maintenance features are integrated with the Health
Monitor. On the following Web site you can find much more detailed
information about the automatic maintenance in DB2 9:
http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.db2.luw.
admin.dbobj.doc/doc/c0021757.html
 Automatic storage management
With automatic storage management, DB2 will allocate storage on demand
as the table consumption grows. This feature intends to be a single point of
storage management for table spaces. DBAs are no longer required to define
the containers for table spaces but just specify a group of storage devices for
DB2, for example, file systems. DB2 creates the necessary containers
automatically across the storage paths. The growth of the existing containers
and the additional new ones is completely managed by DB2. To learn more
about automatic storage management visit the following Web site:
http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.db2.luw.
admin.dbobj.doc/doc/c0052484.html
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DB2 Virtualization
Self-optimization
Self Tuning Memory Manager (STMM), introduced with DB2 9.1, is a
revolutionary feature that manages DB2 memory allocation and usage. STMM is
able to adjust certain memory heaps of DB2 according to the workload of a
database. All those memory heaps are part of the database shared memory set.
Figure 2-4 depicts the different memory sets of DB2.
Database Memory
Database Manager
Shared Memory
Utility Heap
(util_heap_sz)
Hidden Bufferpools
4K
8K
16K
32K
Application Global Memory
(1)
Application
Global Memory
Application
Heap
Application
Heap
(max_connections)
...
Catalog Cache
(catalogcache_sz)
Main Bufferpool(s)
Database
Global Memory
Lock Heap
Lock(locklist)
Heap (locklist)
Database Global Memory
(1)
.. .
Shared sorts
(sheapthres_shr)
(numdb)
Package Cache
(pckcache_sz)
Database Heap (dbheap)
*includes Log Buffer (logbufsz)
Figure 2-4 DB2 memory heaps
STMM constantly monitors the system to make use of or return any free memory
to the OS. It works iteratively to determine an optimal memory configuration for
all heaps. The iterative approach prevents instability of the system. Control
algorithms help determine interval length and prevent oscillations. In each
interval, each heap can grow only by 50% or decrease by 20%.
Chapter 2. Virtualization technologies
21
Figure 2-5 shows the STMM work flow.
Figure 2-5 STMM work flow
Figure 2-6 on page 23 describes the algorithm used for STMM during each
check interval. The general process of this algorithm is:
1. The tuner process wakes from sleep.
2. Determine whether memory configuration is sub-optimal. Some heaps are in
need of memory, while others own more than required.
3. If the DATABASE_MEMORY database configuration (dbm cfg) parameter has
been set to automatic, DB2 checks whether OS has free memory and uses
the free memory from OS to satisfy the needy heaps.
4. If the set value of DATABASE_MEMORY has all been used and there is no
available memory in OS, DB2 will allocate memory from the heaps with
excessive memory to those with a shortage.
5. Continue the process until no more memory can be moved.
6. Determine the tuning frequency based on workload.
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DB2 Virtualization
Figure 2-6 STMM algorithm
More information about STMM can be found at:
http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.db2.luw.admin
.perf.doc/doc/c0021627.html
Compression
A discussion about compression is mainly about saving storage. Storage is
usually the most expensive component of a database solution. Compressing
data can save floor space and personnel cost for managing storage, as well as
power and cooling.
A second aspect is the performance. Compression helps to improve the I/O
efficiency of your database. Because of compression, the database requires
Chapter 2. Virtualization technologies
23
fewer I/O operations to retrieve the same amount of data. This is very important
because accessing data from disk is the slowest database operation.
DB2 9 provides various compression options. The DB2 Storage Optimization
Feature includes all of the compression features except the NULL and default
compression and the Extensible Markup Language/large object (XML/LOB)
inlining. Enabling the DB2 Storage Optimization Feature requires a separate
license that is available for the DB2 9 Enterprise Server Edition only.
In this section we introduce all the compression features. For more information
see:
http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.db2.luw.admin
.dbobj.doc/doc/c0055401.html
NULL and default value compression
These two compression techniques were introduced prior to DB2 9. They are the
first compression features established in DB2. If NULL value compression is
enabled for a table, NULL and zero-length data assigned to the variable-length
data types will not be stored on disk. Default value compression helps you to
further save disk space by not storing inserted/updated values that equal the
system default values.
LOB inlining and XML inlining
XML and large objects (LOBs) are either stored outside the base table in a
separate storage object or, if adequately sized, stored in the formatted rows of
the base table. The adequate size depends on the page size of the table. For
example, for a 32 K page size the maximum size for inlining is 32,669 bytes. The
descriptors stored in the base table rows are used to keep track of the associated
XML/LOB data in the storage object. Figure 2-7 depicts the strategy of inlining.
Figure 2-7 XML and LOB inlining
If a table possesses XML or LOB data that can be stored inline, there are
considerable benefits with respect to performance and storage usage. Inlined
XML or LOBs can be buffered, reducing I/O costs. Storage allocated to the
storage object is reduced by inlining the XML/LOB data in the base table though
the base table storage increases. Inlining small XML/LOBs can result in a
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DB2 Virtualization
noticeable decrease in the net total storage since the decrease in the storage
size is greater than the increase in the base table storage size. XML/LOBs inlined
within the base table data can be compressed when the row compression is
enabled.
Row compression
DB2 9.1 introduces the row compression. It uses a dictionary-based symbol table
and a Lempel-Ziv-based algorithm for compressing and decompressing data
records. The compressed data is replaced by 12-bit symbols. The dictionary is
about 100 KB in size and is stored within the data pages of the compressed
table. The reoccurring strings and trailing or leading blanks are compressed for
the text data. Figure 2-8 shows the effects of the row compression.
Figure 2-8 Row compression
Chapter 2. Virtualization technologies
25
The compressed data remains on disk in the file containers and in the log files. It
also remains compressed in memory in the buffer pools and in the log buffer.
Thus, we achieve significant I/O bandwidth and memory (buffer pool) savings.
DB2 decompresses rows before evaluation. Figure 2-9 depicts all areas where
compressed data resides.
Figure 2-9 Row compression everywhere
Before enabling the row compression on a table, check whether your
environment is CPU bound. In CPU-bound environments performance becomes
worse because of adding the compression and decompression overhead to the
CPU. In I/O-bound environments the I/O savings outperform the overhead of
compression/decompression.
Index compression
Index compression, introduced in DB2 9.7, uses different algorithms from the row
compression. With the index record identifier (RID) list compression, the
database manager can compress an index with a large number of duplicate keys
by storing an abbreviated format of the RID for the duplicate keys. Figure 2-10
illustrates a simple example.
Figure 2-10 Index RID list compression
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DB2 Virtualization
For an index with a high degree of commonality in the prefixes of the index keys,
the database manager can apply compression based on the similarities in
prefixes of index keys. Figure 2-11 shows an example of this algorithm.
Figure 2-11 Index prefix compression
DB2 automatically chooses the most appropriate algorithm to compress indexes.
There is no option available to force DB2 to use a specific algorithm.
Index compression is enabled by default for all indexes on a table that is enabled
for row compression. It is disabled for all indexes when row compression is
disabled for that table. You can overwrite this behavior by using the COMPRESS
YES/NO option with the CREATE/ALTER INDEX statements.
Index compression is not available for multi-dimensional clustering (MDC)
indexes and XML indexes.
Chapter 2. Virtualization technologies
27
Temporary table compression
The temporary table compression is provided in DB2 9.7. It is applicable to user
temporary tables and system temporary tables. User temporary tables are either
declared global temporary tables (DGTTs) or created global temporary tables
(CGTTs). System temporary tables are created by the DB2 engine mainly during
sort or join operations. The compression of temporary tables aims to:
 Reduce the amount of temporary disk space required.
 Have no performance penalty as a result of the extra processing required for
row compression.
 Enhance the query performance.
If the DB2 Storage Optimization Feature is licensed, CGTTs and DGTTs are
compressed automatically by default.
XML compression
This new DB2 9.7 feature has a similar compression approach to the row
compression. XML compression uses a dictionary to replace data that qualifies
for compression. In Figure 2-12 we show the XML compression mechanism.
Figure 2-12 XML compression
2.1.3 Licensing
A major advantage of virtualization is that several virtual machines can run on
the same processor or use just some of the processors in a multi-core
environment. With the former IBM software licensing plan, you would be charged
for the full physical processor capacity of the machine used even if the DB2 VM is
just using a part of a multi-core machine. To provide IBM customers more value
for a lower price, IBM introduced a new licensing model in April 2005 called
sub-capacity licensing. This model was introduced first for the DB2 Enterprise
28
DB2 Virtualization
Edition only. Starting February 2009, this model was valid for all other charged
editions as well. Sub-capacity licensing is especially beneficial for the virtualized
environments because you only pay the license fees for the resources used by
the VM running DB2. The virtualization environments eligible for sub-capacity
licensing are listed on the following Web site:
http://www-01.ibm.com/software/lotus/passportadvantage/Counting_Software_licenses
_using_specific_virtualization_technologies.html
Sub-capacity licensing
For this new licensing model IBM introduces a new unit of measure called
processor value unit (PVU). To help you understand the PVU licensing model, we
first explain some terms used in this context:
 Core: a functional unit within a computing device that interprets and executes
software instructions.
 Chip: electronic circuitry containing, but not limited to, at least one core on a
silicon wafer.
 Socket: the mount that secures a chip to a motherboard.
 Processor: IBM defines a processor as the core. For example, a dual-core
chip has two processor cores on it.
These terms are illustrated in Figure 2-13.
Figure 2-13 Processor definition
Chapter 2. Virtualization technologies
29
A PVU is a unit of measure used to differentiate licensing of middleware on
distributed processor technologies (defined by processor vendor, brand, type,
and model number). IBM defines a certain PVU value per core for each of the
supported processor types. Figure 2-14 lists the PVU definitions for different
processor types.
Figure 2-14 PVU definitions
The most current PVU definitions can be found at:
http://www-01.ibm.com/software/lotus/passportadvantage/pvu_licensing_for_customers.
html
30
DB2 Virtualization
Figure 2-15 shows that DB2 is running in a partition that uses three processor
cores in a six-processor-core activated architecture. With the full-capacity
licensing model, the license PVUs for six processor cores will be charged. With
the cost-saving sub-capacity model, you only must pay the license for three
cores.
Figure 2-15 Sub-capacity licensing
Sub-capacity licensing using PVUs provides:
 A licensing structure that avoids fractional licensing or processor factors for
multi-core chips
 Flexibility and granularity, enabling customers to run a product on as few or as
many processor cores as they require
 The capability to deliver software price performance improvements as new
processor families are introduced
 A sustainable licensing foundation for the future
 Transferability of licenses across distributed systems
All DB2 editions are eligible for PVU licensing. For more detailed information
refer to the following Web page:
http://www.ibm.com/software/lotus/passportadvantage/subcaplicensing.html?Open
Document
2.2 PowerVM on Power Systems
PowerVM is the new brand for Power Systems virtualization. It is a combination
of hardware, firmware, and software that provides virtualization for CPU,
network, and disk. It implements a hardware-assisted virtualization technique.
Chapter 2. Virtualization technologies
31
PowerVM on Power Systems offers industry-leading virtualization capabilities for
AIX and Linux. With the Standard Edition of PowerVM (PowerVM-SE),
micro-partitioning allows businesses to increase the utilization of their servers,
with server definitions down to one-tenth of a processor and the ability to allow
server size to flex with demand. In addition, with PowerVM-SE, there is the
Virtual I/O Server, which allows the sharing of expensive disk and network
resources, while minimizing any management and maintenance costs.
With the introduction of the PowerVM Enterprise Edition, all of these features are
joined by the ability to migrate running partitions and their applications from
server to server. Combining these PowerVM features, we can help today's
businesses further transform their computing departments into the agile,
responsive, and energy-efficient organization demanded by today's enterprises.
We discuss more details about the PowerVM capabilities in Chapter 3, “Power
Systems and PowerVM” on page 47. Detailed information also can be found at:
http://www.redbooks.ibm.com/abstracts/sg247940.html
Table 2-3 on page 15 provides a list of supported operating systems.
POWER Hypervisor
The POWER® Hypervisor™ is the foundation of IBM PowerVM. Combined
with features designed in the IBM POWER processors, the POWER Hypervisor
delivers functions that enable capabilities including dedicated-processor
partitions, micro-partitioning, virtual processors, IEEE VLAN compatible virtual
switch, virtual Ethernet adapters, virtual SCSI adapters, and virtual consoles.
32
DB2 Virtualization
The POWER Hypervisor is a firmware layer sitting between the hosted operating
systems and the server hardware, as shown in Figure 2-16. The POWER
Hypervisor is always installed and activated, regardless of system configuration.
It is controlled and managed by Hardware Management Console (HMC), the
focal management point of Power Systems. The POWER Hypervisor has no
specific or dedicated processor resources assigned to it.
Figure 2-16 POWER Hypervisor
In partitioned environments where business-critical applications are consolidated
onto the same hardware, exceptional availability and serviceability are needed.
This ensures a smooth recovery from unplanned service interruptions. The
POWER Hypervisor ensures that issues affecting one partition do not propagate
into other logical partitions on the server.
The POWER Hypervisor does not own any physical I/O devices, nor does it
provide virtual interfaces to them. All physical I/O devices in the system are
owned by logical partitions or the Virtual I/O Server. To support virtual I/O, the
POWER Hypervisor provides:
 Control and configuration structures for virtual adapters
 Controlled and secure transport to physical I/O adapters
 Interrupt virtualization and management
Chapter 2. Virtualization technologies
33
HMC
The primary hardware management solution that IBM has developed relies on an
appliance server called HMC, packaged as an external tower or rack-mounted
server.
The HMC is a centralized point of hardware control. A single HMC can handle
multiple POWER5™ and POWER6® systems, and two HMCs may manage
the same set of servers in a dual-active configuration, providing resilience.
Hardware management is done using the HMC interface (Web-browser-based
starting with HMC Version 7), which communicates with the servers using a
standard Ethernet connection to the service processor of each POWER5 or
POWER6 system. Interacting with the service processor, the HMC is able to:
 Create, manage, and modify logical partitions.
 Modify the hardware configuration of the managed system.
 Manage the service calls.
The HMC also provides functions to simplify the management of the Virtual I/O
Server environment. It is also possible to execute Virtual I/O Server commands
from the HMC.
Virtual I/O Server
The Virtual I/O Server is part of the IBM Power Systems PowerVM Standard
Edition or Enterprise Edition hardware feature. The Virtual I/O Server allows the
sharing of physical resources between partitions to allow more efficient
utilization. The Virtual I/O Server can use both virtualized storage and network
adapters, making use of the virtual small computer system interface (SCSI) and
virtual Ethernet facilities.
For storage virtualization, these storage devices can be used:





Direct-attached entire disks from the Virtual I/O Server
SAN disks attached to the Virtual I/O Server
Logical volumes defined on either of the previous disks
File-backed storage, with the files residing on either of the first two disks
Optical storage devices
For virtual Ethernet we can define Shared Ethernet Adapters on the Virtual I/O
Server, bridging network traffic from the virtual Ethernet networks out to physical
Ethernet networks.
34
DB2 Virtualization
The Virtual I/O Server technology facilitates the consolidation of LAN and disk
I/O resources and minimizes the number of physical adapters that are required,
while meeting the non-functional requirements of the server. Figure 2-17 shows a
very basic overview of a Virtual I/O Server configuration.
Figure 2-17 Virtual I/O Server
Live Partition Mobility
Live Partition Mobility, licensed through PowerVM Enterprise Edition, is a feature
that relies on a number of different components, including:
 POWER Hypervisor
 Virtual I/O Server
 Hardware Management Console
Live Partition Mobility allows you to move running AIX or Linux partitions from
one physical POWER6 server to another without disruption. The movement of
the partition includes everything that partition is running, that is, all hosted
applications. Some possible applications and advantages are:
 Moving partitions from servers to allow planned maintenance of the server
without disruption to the service and users
 Moving heavily used partitions to larger machines without interruption to the
service or disruption to users
Chapter 2. Virtualization technologies
35
 Moving partitions to appropriate servers depending on workload demands
and adjusting the utilization of the server-estate to maintain an optimal level of
service to users at the optimal cost
 Consolidation of under utilized partitions out-of-hours to enable unused
servers to be shut down, saving power and cooling expenses.
2.3 VMware vSphere
VMware vSphere (that is, Virtual Infrastructure 4) is a virutalization solution that
delivers IT infrastructure as a service, masking all the complexity of the
infrastructure and exposing an easily accessible service to applications. It
consists of products and features including:
 A set of infrastructure vServices to aggregate and allocate on-premise
servers, storage, and network for maximum infrastructure efficiency
 A set of cloud vServices to federate the on-premise infrastructure with
third-party cloud infrastructure
 A set of application vServices to guarantee the correct levels of availability,
security, and scalability to all applications independent of hardware and
location
 A set of management vServices that allow you to manage proactively the
virtual datacenter operating system and the applications running on it
Unlike a traditional operating system, which is optimized for a single server, the
virtual data center operating system serves as the operating system for the entire
data center.
In this section we introduce some of the vSphere features. In Chapter 4,
“VMware vSphere” on page 75, we discuss more details about the VMware
products. For more information directly from VMware, visit:
http://www.vmware.com/
36
DB2 Virtualization
ESX
VMware ESX is a full virtualization environment. VMware provides isolated guest
environments called virtual machines. The guest OS is not aware that it is being
virtualized and requires no modification. No separate master or parent virtual
machine is required to start the guest virtual machines. Figure 2-18 shows how
this architecture is built.
Figure 2-18 VMware ESX
VMware can virtualize any x86 operating system. For supported operating
systems, check Table 2-1 on page 14.
2.3.1 vCenter
VMware vCenter Server is the universal hub for virtualization management that
focuses on managing pooled infrastructures instead of individual components.
vCenter is designed to aggregate physical hardware (networking, storage,
memory, and CPU) and manage it as a collection of resources that can be
allocated dynamically on business needs.
VMware’s vCenter management platform provides a proven approach to
managing the virtualized datacenter, allowing you to streamline IT management
and reduce operating costs.
2.3.2 VMotion
VMware VMotion technology enables you to move an entire running virtual
machine instantaneously from one server to another. Virtual Machine File
System (VMFS), VMware’s cluster file system, is used to control access to a
virtual machine’s storage. The active memory and the current execution state of
Chapter 2. Virtualization technologies
37
a virtual machine are transmitted from one physical server to another using a
high-speed network connection. The access to the virtual machine’s disk storage
is switched to the new physical host. The virtual machine retains its network
identity and its connections because the network is also virtualized by ESX.
VMware VMotion allows you to perform live migrations with zero downtime.
2.3.3 Distributed Resource Scheduler
Distributed Resource Scheduler (DRS) continuously monitors utilization across
resource pools. It provides the capability to create rules and policies to prioritize
how resources are allocated to virtual machines. This enables you to balance
your computing capacity among the different resource pools and virtual
machines. DRS capabilities ensure that each virtual machine has access to
appropriate resources at any point in time. If additional resources are made
available to DRS, it will take advantage of them by redistributing virtual machines
without system disruption.
2.4 Hyper-V
Hyper-V comes with Microsoft Windows Server 2008. It is a hardware-assisted
solution that provides isolated operating system environments called partitions.
One so-called parent partition running Windows 2008 is required. This parent
partition is also known as a root partition. From within this parent partition other
partitions, named child partitions, can be started. They host the guest operating
systems. Figure 2-19 shows this architecture.
Figure 2-19 Hyper-V
38
DB2 Virtualization
For supported operating systems check Table 2-1 on page 14. You can retrieve
more detailed information from the following Web site:
http://www.microsoft.com/windowsserver2008/en/us/hyperv-main.aspx
2.5 Linux Kernel-based Virtual Machine (KVM)
KVM is the new Linux Kernel-based Virtual Machine. It is a hardware-assisted
virtualization solution. As the name indicates, KVM is integrated into the Linux
kernel. Therefore, the Linux kernel itself becomes the hypervisor. This approach
takes advantage of all the improvements made to the Linux kernel, as they
become beneficial for the hypervisor as well.
The KVM virtualization solution requires processors that support virtualization for
different operating systems. KVM itself is responsible for virtualizing the memory
and QEMU. A processor emulator is required to virtualize the I/O. QEMU
virtualizes disks, graphic adapters, network devices, and so on. A copy of it runs
in each guest system. Any I/O requests that a guest operating system makes are
routed to be emulated by the QEMU process.
As the hypervisor is a part of a regular Linux kernel, you can run any Linux
application on the hypervisor. The guest operating systems run on the top of the
hypervisor, each one in a separate process. Figure 2-20 provides an overview of
the KVM architecture.
Figure 2-20 KVM architecture
For more information see:
http://www.linux-kvm.org/page/Main_Page
Chapter 2. Virtualization technologies
39
2.6 z/VM
The z/VM hypervisor offers a base for customers who want to exploit IBM
virtualization technology on the IBM System z10 servers. It provides a full
virtualization environment on IBM System z servers, allowing several guest
operating systems on these servers. Besides the various System z platform
operating systems, z/VM also allows Linux operating systems to run on the IBM z
servers. Figure 2-21 shows these features.
Figure 2-21 z/VM features
For supported operating systems check Table 2-3 on page 15. For more detailed
information see:
http://www.vm.ibm.com/
40
DB2 Virtualization
2.7 Xen
Xen is an open-source paravirtualization product that runs on various processors
such as IA-32 (x86, x86-64), IA-64, and PowerPC 970. During startup Xen boots
a first guest operating system called domain 0 (dom0). This domain receives
special management privileges to maintain the other guest operating systems
running in domain U (domU). Figure 2-22 depicts this architecture.
Figure 2-22 Xen architecture
For supported operating systems check Table 2-1 on page 14. You can find more
detailed information at:
http://www.xen.org/
Chapter 2. Virtualization technologies
41
2.8 Parallels Virtuozzo Containers
Parallels Virtuozzo Containers is an operating system-level virtualization product
designed for large-scale homogenous server environments and data centers.
This solution is compatible with x86, x86-64, and IA-64 platforms. It creates
isolated partitions or containers on a single physical server and operating system
instance to utilize hardware and software. Figure 2-23 depicts the architecture of
Parallels Virtuozzo Containers.
Figure 2-23 Parallels Virtuozzo Containers architecture
For supported operating systems check Table 2-2 on page 15. You can find more
detailed information at:
http://www.parallels.com/products/virtuozzo/
2.9 Solaris Zones (containers)
Solaris Zones (non-global zones) are complete execution environments for
applications within a single Solaris instance called the global zone. A zone allows
application components to be isolated from each other by mapping system
resources to non-global zone interfaces. The zone definition establishes
boundaries for resource consumption, as well as providing isolation from other
42
DB2 Virtualization
zones on the same system. Figure 2-24 depicts the virtualization approach of
Solaris Zones.
Figure 2-24 Solaris Zones
For supported operating systems check Table 2-4 on page 15. To read more
about this topic see:
http://www.sun.com/software/solaris/containers_learning_center.jsp
2.10 HP Integrity VM
HP Integrity Virtual Machines (Integrity VM) is a soft-partitioning and
virtualization technology that enables you to create multiple software-controlled
Itanium-based virtual machines within a single HP Integrity server or nPartition.
The Integrity server or nPartition acts as a VM Host for the virtual machines.
(Virtual machines are also called guests.) The VM Host is a platform manager. It
manages hardware resources such as memory, CPU allocation, and I/O devices,
and shares them among multiple virtual machines. The VM Host runs a version
of the HP-UX operating system and can be managed using standard HP-UX
management tools.
The virtual machines share a single set of physical hardware resources, yet each
virtual machine is a complete environment in itself and runs its own instance of
Chapter 2. Virtualization technologies
43
an operating system (called a guest OS). As with a real machine, the virtual
machine contains:







At least one processor core, also referred to as a virtual CPU or vCPU
Memory
Disks
Networking cards
A keyboard
A console
Other components of a computer
All these elements are virtual, meaning that they are at least partially emulated in
software rather than fully implemented in hardware. However, to the guest OS
they appear as though they are real physical components.
No guest OS can access memory allocated to another guest OS. One virtual
machine is not affected by software events on another virtual machine, such as
faults or planned software downtimes. Integrity VM optimizes the utilization of
hardware resources, quickly allocating resources such as processor cores,
memory, or I/O bandwidth to the virtual machines as needed. Any software that
runs on supported versions of HP-UX can run in an Integrity VM virtual machine.
No recompiling, recertification, or changes are required for applications to run in
a guest OS. Applications run in the guest OS as they do on any operating
system.
Figure 2-25 depicts the virtualization architecture of the HP Integrity VM.
Figure 2-25 HP Integrity VM
44
DB2 Virtualization
For supported operating systems check Table 2-3 on page 15. More information
can be found at:
http://docs.hp.com/en/
Chapter 2. Virtualization technologies
45
46
DB2 Virtualization
3
Chapter 3.
Power Systems and
PowerVM
IBM Power Systems offers well-developed and full-grown virtualization
capabilities, which have been used together with DB2 for a long time. In fact,
since the operating systems running on Power Systems have been virtualized for
quite a while, most of the database administrators working with DB2 running on
Power Systems are so used to the virtualization that they do not pay any
attention to it.
Virtualization on Power Systems is implemented through the PowerVM
virtualization technology. PowerVM is the combination of hardware and software
technologies that together provide the virtualization capabilities. It provides a set
of rich features that include maintenance tools to set up, maintain, and monitor
virtualized Power Systems environments.
In this chapter we discuss the following topics:
 PowerVM virtualization terminology, capabilities, features, and architecture
 How to set up Power Systems and PowerVM optimized for different DB2
workload scenarios
 How to set up and configure DB2 to get the most out of the virtualized
environment on Power Systems and PowerVM
© Copyright IBM Corp. 2009. All rights reserved.
47
3.1 Architecture
PowerVM architecture consists of the following main components and features:








POWER Hypervisor (PHYP)
Hardware Management Console (HMC)
Integrated Virtualization Manager (IVM)
Logical partition (LPAR)
Dynamic logical partitioning
Virtual I/O Server (VIOS)
Live Partition Mobility (LPM)
Workload partition (WPAR)
In the following subsections we explain these components and the features
related to each of them.
3.1.1 POWER Hypervisor
A hypervisor acts as a layer between the physical server and all of the virtual
servers running on top of it. It is required in order to run one or more virtualized
machines on a hardware set. The POWER Hypervisor is integrated in all current
Power Systems servers as part of the system firmware. Since the introduction of
POWER5, the POWER Hypervisor is active on all Power Systems servers. It is
not possible to run a server on POWER5 or POWER6 without it being virtualized.
3.1.2 Hardware Management Console
The Hardware Management Console is the primary hardware management
solution for Power Systems servers. With one HMC you can manage multiple
POWER5 and POWER6 servers. The HMC is a dedicated server running on
separate hardware. Since Version 7, the HMC user interface has been Web
based.
The HMC is the focal management point for your Power Systems server
environment and hardware. It communicates to the servers using a standard
Ethernet connection to the service processor of each Power Systems server. You
can utilize the HMC to initially create your logical partitions, as well as change
parameters and assigned resources afterwards.
3.1.3 Integrated Virtualization Manager
The Integrated Virtualization Manager is, just like the HMC, used to initially
create and maintain logical partitions. However, the IVM performs a subset of the
48
DB2 Virtualization
HMC for only a single Power Systems server. The IVM is integrated within the
Virtual I/O Server product.
3.1.4 Logical partition
A logical partition can be seen as a virtual machine itself. The entire Power
Systems server can be divided into one or more LPARs, where each can run its
own operating system (OS). These operating systems are isolated from each
other just like normal physical servers. You are able to interact with the LPARs
just as you are able to interact with any physical server.
When dividing your Power Systems server into LPARs you can choose from two
different partitioning methods, depending on how you decide to share your
processor capacity between the LPARs. These two partitioning methods are:
 Shared processor partition
 Dedicated processor partition
Here we discuss both of the partition types and their capabilities and features in
more detail.
Shared processor partition
Shared processor partitioning has been available since POWER5 was
introduced. This method implements micro-partitioning, where a fraction of the
CPU attached to the system can be assigned to the LPAR. You are able to slice
your CPU into units of one-hundredth (1/100th) of the CPU capacity, but the
minimum amount of physical CPU given to a specific LPAR is one-tenth (1/10th).
For example, by using shared processor partitioning, you are able to partition
your 8-way Power Systems server to as many as 80 partitions, although it might
not be the most efficient partitioning plan to have such a large amount of small
partitions.
When using micro-partitions you can define how much CPU capacity your LPAR
is entitled to use. You can think of your Power Systems CPUs as a pool from
which CPU capacity will be assigned to the shared processor partitions.
Remember that you are able to assign the CPU resources from this pool using
fractions of a CPU and not just entire CPUs. To define the partitions, you must
initially set the minimum processing units, the desired processing units, and the
maximum processing units:
 Minimum processing units
This is the minimum CPU resource units required to activate a LPAR. If the
available CPU resource units do not meet the number defined in this
parameter, the partition will not be activated. When dynamically changing the
Chapter 3. Power Systems and PowerVM
49
number of virtual processors assigned to the system, this parameter sets the
lower limit.
 Desired processing units
With this you define the value that you want to give to a partition. As long as
there are enough CPU resource units to meet the minimum processing unit
value, the partition will be activated even if there are not enough CPU
resource units available to satisfy the number defined in this parameter. When
there are enough free processing units to fulfill what was defined in desired
processing units, this will be guaranteed for a logical partition. You are able to
change this value while the system is online. This value is shown as the
entitled capacity at the OS level.
 Maximum processing units
This value defines the maximum processing units available for a logical
partition when you want to dynamically increase the amount of the processing
units for this partition. This parameter does not define how much processing
capacity an uncapped partition can use. Uncapped partitions can temporarily
exceed the number of processing units defined in this parameter.
There are also two modes for shared processor partitions:
 Capped
With this method your CPU resources for the logical partition are limited to the
maximum processing units value defined for the logical partition. The partition
cannot go beyond the limit defined in the maximum processing units at any
time without changing its entitled capacity, either dynamically or by changing
the partition profile.
 Uncapped
With this method, when there are free resources available in the shared
processor pool, your CPU resources for a logical partition can go beyond the
value defined in the desired processing units up to the number of virtual
processors.
If there is contention with the CPU resources from the shared processor pool
between logical partitions defined as uncapped, the capacity will be shared
among the partitions based on their initially defined uncapped weight value.
This value can range from 0 to 255, where 0 is the lowest priority and 255 is
the highest priority. The default value for the uncapped weight is 128.
Shared processor pool
Since POWER6, shared processor partitions can share more than one shared
processor capacity pool. For the examples in this book, we use only one shared
processor pool. There is always the default shared processor pool called
50
DB2 Virtualization
Shared-Processor Pool0 . Besides the default shared processor pool, you can
define as many as 63 additional multiple shared processor pools.
Virtual processors
A virtual processor represents a single physical processor to the guest operating
systems running on the logical partition. One physical processor can be divided
into up to 10 virtual processors. When you define a profile for a logical partition,
you must set three parameters related to the virtual processor:
 Minimum virtual processors
This parameter defines the minimum number of virtual processors that must
be available for this partition when it is activated. When dynamically changing
the number of virtual processors assigned to the partition, this parameter sets
the lower limit.
 Desired virtual processors
This is the desired virtual processor number for a LPAR. When a LPAR is
activated the hypervisor will try to assign the number of virtual processors to
this value. You can set this parameter to any value between the minimum
number of virtual processors and the maximum number of virtual processors
and change it while the system is online.
 Maximum virtual processors
This parameter sets the upper boundary of the number of virtual processors
assignable for a logical partition.
Dedicated processor partition
For a dedicated processor partition you are able to assign one or more dedicated
processors to an LPAR. For instance, if your server has eight processors, you
can partition it to four 2-way LPARs, each having two dedicated physical
processors. Since POWER6, you are also able to share the unused CPU cycles
of the dedicated processor partitions with the shared processor partitions. In this
way you can ensure maximum usage and capacity for your Power Systems
servers and LPARs.
For the shared processor partitions, you must define minimum, desired, and
maximum values for the processor and memory capacity. For the dedicated
processor partitions, there is always a guaranteed amount of dedicated
processor capacity that is mapped to actual physical processors. This is why you
do not define virtual processors for the dedicated processor partition. The
number of desired processors is shown as the entitled capacity in the OS level.
Chapter 3. Power Systems and PowerVM
51
Partitioning example
You can combine the two partitioning methods, shared processor partitions and
dedicated processor partitions, on one Power Systems server. For instance, you
can have a system with eight physical processors partitioned into three dedicated
processor partitions and three shared processor partitions. For the three
dedicated processor partitions, two LPARs have a dedicated physical processor
each and one LPAR has two dedicated physical processors. The other four
physical processors are assigned to the shared processor partitions.
Figure 3-1 illustrates this example of partitioning a Power Systems server by
using dedicated and shared processor partitions.
Figure 3-1 LPAR with dedicated and shared processor partitions
In this example the shared processor partitions are micro-partitioned so that
LPAR 4 has 1.8 times one physical CPU capacity, LPAR 5 has 1.2 times one
physical CPU capacity, and the remaining LPAR 6 has 0.6 times one physical
CPU capacity. This leaves us free capacity of 0.4 CPUs to be used for uncapped
mode partitions in the shared processor pool. If we have configured all our
LPARs in the shared processor pool to operate in uncapped mode, this would
mean that the remaining extra capacity will be shared on an as-needed basis
between the LPARs based on their uncapped weight value, which is the same for
all by default.
To illustrate the concept of virtual processor, in this example we can configure
LPAR 4 to have four virtual processors, LPAR 5 to have two virtual processors,
and LPAR 6 to have two virtual processors, even though the physical CPU
assigned to these LPARs is just a fraction of the total four shared processors.
The number of virtual processors is not necessarily related to the actual CPU
capacity that the LPAR is assigned to use. Later in this chapter we go through the
best practices for how to define the virtual processors for the LPARs on the
shared processor pool.
52
DB2 Virtualization
3.1.5 Dynamic logical partitioning
With the dynamic logical partitioning (DLPAR) feature you can change assigned
resources for the logical partitions without rebooting the operating system
running on a partition. This means that you are able to change the amount of
memory or processing units for your LPAR without a service break. This feature
is very useful. For instance, you can add additional CPU resources to a logical
partition that is temporarily running out of CPU resource and remove the
resource once it is no longer needed.
When you define values for the maximum processing units or for the maximum
memory, keep in mind that these values define the upper limit for how far you can
dynamically add resources to the logical partition without rebooting your partition.
However, too large of a value for the maximum memory parameter causes the
hypervisor to consume an unnecessary amount of memory.
The concept of setting the limits for the processing units on a LPAR can be
applied to the memory. There are minimum, desired, and maximum values for
memory when initially setting up a LPAR or when changing its profile. These
parameters define the upper and lower memory limits for a specific LPAR. You
can change the values by changing the profile for LPAR through the HMC or the
Integrated Virtualization Manager (IVM).
3.1.6 Virtual I/O Server
With the VIOS you can assign physical resources such as storage devices and
network devices across logical partitions. The main benefit of VIOS is that you
can virtualize the physical I/O devices, allowing you to share one physical device
with one or more virtual servers. You are not bound to get dedicated individual
physical peripherals for the number of LPARs that you are running on your Power
Systems server. This saves hardware costs and makes the maintenance easier
even for a large number of servers.
VIOS is a stripped-down version of the AIX OS. Its only function is to take care of
I/O virtualization for other LPARs relying on the server. Let us take a closer look
at the features and the benefits of virtualizing storage and network:
 Virtual storage
With VIOS you are able to virtualize
– Direct-attached storage (DAS): You are able to virtualize physical storage
devices as a whole. With certain restrictions, these storage devices can be
moved between two VIOSs or between different LPARs.
– Storage area network (SAN) disks: You are able to virtualize SAN disks
from your centralized storage network for individual LPARs. However,
Chapter 3. Power Systems and PowerVM
53
logical volumes cannot be virtualized through multiple VIO servers,
making them unsuitable for configurations requiring redundancy.
– Logical volumes: You are able to virtualize logical volumes for LPARs. The
LPARs will see virtualized logical volume as physical disks. This is
beneficial since it reduces the need for physical peripherals.
 Virtual network
One of the main benefits for the virtual network is that it not only reduces the
requirements for network peripherals, but also makes it easier to increase
availability for the network devices used by LPARs.
There are several methods to provide continuous network availability such as
dead gateway detection (DGD), virtual IP addresses (VIPAs), and IP address
takeover (IPAT). By using failover techniques and one or more virtual I/O
servers, you are able to provide continuous network access to the logical
client partitions. Shared Ethernet Adapter (SEA) failover features, combined
with other available network failover techniques, not only provide the
continuous network access, but also lessen the amount of network equipment
required on the server system.
To provide continuous access to I/O resources you must have the traditional
failover techniques in your architecture. These include multi-path I/O (MPIO)
access to disks as well as redundant disk devices. When using VIOS this might
not be enough since you also must be prepared for VIOS downtime. For
instance, a planned outage for performing a VIOS software update must be
allowed without causing service downtime. To achieve this goal, you can have
more than one VIOS on your system. For smaller systems one virtual I/O server
might be sufficient. However, for larger system setup, it is good to have two or
more virtual I/O servers on one system. When Virtual I/OS servers and clients
are properly configured, the clients are able to utilize peripherals from another
VIOS while one is unavailable during a system upgrade.
3.1.7 Live Partition Mobility
The Live Partition Mobility feature was introduced on POWER6 hardware and is
not available on earlier hardware releases. With LPM you are able to move your
logical partitions from one hardware to another without powering down the LPAR.
With this feature you can perform hardware upgrades without a service break.
This greatly increases your system availability on mission-critical systems, where
continuous service is needed 24x7.
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DB2 Virtualization
Using this feature is preferred in migrating partitions. There are two types of
migration:
 Inactive migration
 Active migration
LPM can be used with DB2 as well. To find more information about DB2 and
LPM, refer to the IBM white paper DB2 and Power Systems PowerVM Live
Partition Mobility, available at:
https://www-304.ibm.com/jct09002c/partnerworld/wps/servlet/ContentHandler/white
paper/aix/v6r1_db2_powervm/live_partition?pageId=pw.technical.resources
3.1.8 Workload partition
WPAR is a software-based virtualization solution introduced with AIX 6.1. WPAR
is supported on POWER4, POWER5, and POWER6. There are two types of
WPAR:
 System WPAR
 Application WPAR
At the time that this book was written, DB2 is supported only on System WPAR.
System WPAR
You can have multiple System WPARs running on one LPAR. Essentially, a
WPAR uses OS-level virtualization, and a LPAR is based on full virtualization, so
a WPAR is a virtual instance within a virtual machine. System WPARs are
isolated from each other and can have their own IP addresses and file systems.
Although they can share the global environment and /usr and /opt file systems,
the sharing is in read-only mode. You can run one or more full operating WPAR
environments with its own applications on one LPAR. With System WPAR you
can, for example, run two or more instances of DB2 totally isolated from each
other on different IP addresses. One instance can be used for testing while the
other instance can be used for development.
Application WPAR
Application WPAR makes it possible to isolate applications or groups of
applications from each other. Applications running on different application
WPARs cannot see or communicate with each other on the process level, but
they do share the file systems of the global environment.
Live Application Mobility
Live Application Mobility allows you to move your workload partitions from one
system to another. You are able to migrate your applications from one LPAR to
Chapter 3. Power Systems and PowerVM
55
another without causing any service outage. The LPAR that you are moving your
application to can be located on the same physical server or on a separate
physical server.
For more information about WPAR and its features, refer to IBM Redbooks
publication Introduction to Workload Partition Management in IBM AIX Version
6.1, SG24-7431, at:
http://www.redbooks.ibm.com/Redbooks.nsf/RedbookAbstracts/sg247431.html
3.1.9 Overall architectural picture
In the example illustrated in Figure 3-1 on page 52, we only cover how the logic
of virtualization on Power Systems works, but we do not include how the actual
physical hardware is seen by the logical partitions. To bring together the main
components of virtualization under Power Systems that we have discussed so
far, Figure 3-2 illustrates how these components are virtualized.
Figure 3-2 Overall architectural picture
The difference between Figure 3-2 and Figure 3-1 on page 52 is that we used
one of the dedicated-processor LPARs as the VIOS and left only five partitions
for application servers. VIOS virtualizes the underlying physical I/O peripherals
for sharing among other LPARs. POWER Hypervisor is between other system
resources and does the sharing and allocation of CPU and random access
memory (RAM) just as it did on the previous example, although the physical
peripherals were not included in Figure 3-1 on page 52. Besides RAM and CPU,
we also have host bus adapters (HBAs) and network interface cards (NICs)
attached to our system. Both NICs and RAM are virtualized by VIOS, and LPARs
56
DB2 Virtualization
are able to utilize them just as they have their own dedicated hardware
resources. However, these actual physical devices are shared among the LPARs.
3.2 Power Systems and PowerVM setup
When setting up a Power Systems environment, there are many options that you
must consider and plan properly ahead of time in order to achieve the optimal
performance goal. Especially for a database server, the database system is the
primary application in the system and database configuration considerations
should also be incorporated in the Power Systems planing setup. However, the
Power Systems setup tasks are usually performed by the system support team
without DBA’s involvement, or the DBA may not have the expertise in this area. In
this section we discuss the Power Systems setup, concentrating on providing
useful tips for setting up a virtualized environment for DB2 running on the Power
Systems server. We discuss the following items:
 Setting up and configuring logical partitions
– Choosing a partition type
– Configuring physical and virtual processors
– Configuring the memory
 Considerations for disk storage and choosing from different options
 Considerations for the network and choosing from different options
 Setting up the VIOS
Power Systems environment planning
Dynamic logical partitioning provides an easier option to fix bottlenecks on CPU
or memory resources. This is achievable since the hardware can be shared with
the LPAR running the database engine. On the other hand, in online transaction
processing (OLTP) and especially data warehouse (DW) environments, the
bottleneck is most often the I/O on the disk storage. This makes planning the disk
setup on both database and system levels the most important area.
For CPU and memory capacity you should carefully investigate your workload
and setup requirements. Usually, requirements for CPU and memory are
relatively easy to define through the load tests. Some references can also be
derived from the proof-of-concept environments as well as from the development
and test systems. On partitioned environments, the memory and CPU capacity is
easily changed as long as there is enough capacity on the Power Systems server
to be utilized.
Chapter 3. Power Systems and PowerVM
57
In partitioned environments there are a few additional settings that must be
planned carefully when compared with the traditional systems running on bare
metal. The additional settings to be considered are:
 Number of minimum, desired, and maximum processors
 Number of minimum, desired, and maximum virtual processors
 The amount of minimum, desired, and maximum memory
 For disk storage, choosing the storage type between different types of local
storage and storage options provided by VIOS
 Deciding on either a dedicated processor partition or a shared processor
partition running in capped or uncapped mode
 Choosing the network setup from a locally attached network and different
options that VIOS provided
Choosing the LPAR type
You must choose between a dedicated and a shared processor partition.
Dedicated processor partitions can have one or more processors exclusively
reserved for them. PHYP schedules the same physical cores for the dedicated
processor partitions, which makes it possible for the dedicated processor
partitions to benefit from a warm CPU cache. Although this could be beneficial
for the database servers, the actual benefits that the database servers received
usually are less than what is expected. Although you can benefit from dynamic
logical partitioning and change the amount of both physical processors and
memory assigned to the dedicated partition, you are not able to benefit from the
shared processor pool at peak times. This is why we recommend shared
processor partitions for DB2 partitions unless there is a special need for an
isolated dedicated partition.
You should set the LPAR for a database server as a shared processor partition in
uncapped mode to be able to utilize the shared processor pool. The uncapped
shared processor pools are very effective for the workloads that vary on at
different times and when workloads are unpredictable. Ensure that you tune the
uncapped weight properly to prioritize the shared processor pool usage among
the partitions. You can also consider putting all the DB2 server LPARs into a
separate processor pool to optimize your DB2 license usage.
Memory settings
When setting up the LPAR you should set the amount of desired memory the
same way as you would set it for a non-virtualized server. This amount depends
on the database requirements, for instance, the size of buffer pools that are
required for your workload. Since the DB2 server is running on a logical partition,
it is able to utilize dynamic logical partitioning. For setting the maximum memory
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DB2 Virtualization
size, you should consider setting a high number, including a prediction of future
room for growth.
When setting the maximum memory size, you must consider the hypervisor
overhead and your memory requirements. Here are some guidelines:
 As a minimum, round up the amount of memory to the nearest power of two.
This does not cause any overhead.
 For future growth, multiply the value obtained above by two. This allows at
least doubling the amount of memory without production break.
For example, if you have a partition that requires 5 GB of memory, rule 1 would
give you 8 GB, and rule 2 would double that to 16 GB.
Processor settings
The same as with the memory settings, you should set the desired processor
capacity based on the actual need. If your workload is going to change, set the
amount of actual physical processor capacity high enough to allow changes in
the future. Usually, as time progresses, the need for both memory and CPU
usage will grow as the amount of data and the number of rows in the tables
increase. Dynamic logical partitioning helps to provide continuous service
without breaks even when the capacity demands have changed.
Since there is virtually no overhead in having a large number of maximum
processing units, consider setting the maximum processing units for all partitions
to the number of processors in your server.
Number of virtual processors
Since the DB2 server will be running on the same physical hardware as other
servers, it is not enough to just specify the need for processor capacity for the
database logical partition. You must tune the logical partitions with the
consideration of the overall effectiveness on the system. By setting the number of
virtual processors for your DB2 server, you can influence the total system
performance as well as the performance of one specific logical partition.
By setting up the number of virtual processors, you set up how small the fractions
are that are used to divide the physical processor capacity for the logical
partitions. By setting this value, you set the ratio between physical and virtual
processors. The number of virtual processors is the number of processors that
the OS running on the logical partition will see that it has as though they are
physically attached to it. The OS scheduler does not distinguish between virtual
or physical processors. It schedules the workloads as though the virtual
processors were physical ones, whereas PHYP can schedule physical CPU
cycles the way that it sees the best. There is no straight connection between how
these physical CPU cycles are divided among the LPARs and the virtual
Chapter 3. Power Systems and PowerVM
59
processors. However, in general, from the entire system point of view, the more
virtual processors are defined, the better CPU resource utilization will be. For
each individual LPAR, if the number of virtual processors defined for the LPAR is
equal to or is the round-up value of the defined desired physical processor, the
LPAR is guaranteed the maximum available CPU resources.
You can use following formula to derive the number of virtual processors:
RVP = {round up (CEC + [UW/TUW] * FPC) , round up (CEC + FPC)}
Where:
RVP
Represents the rounded-up range of virtual processors.
EC
Is the current entitled capacity.
UW
Is the uncapped weight for the shared processor partition.
The default value is 128, and the range is 0–255.
UW
Is the total uncapped weight of all uncapped shared
processor partitions.
PC
Is the free-pool capacity (free unassigned processor
capacity).
This formula gives you a range from which to choose the value for the desired
virtual processors. When using this formula you should also consider the
following:
 The number of the rounded-up value for virtual processors should not go
beyond two virtual processors per one entitled physical processor.
 To maximize total system processor utilization, use the higher number of
virtual processors derived with the formula.
 To optimize the performance of the corresponding logical partition, use the
lower number of virtual processors derived from the formula.
Network type
You can choose from three different types of network:
 Shared Ethernet Adapter (SEA)
 Virtual Ethernet
 Locally attached network adapter
SEA requires VIOS, and the two later options are provided directly through
PHYP. The advantage of SEA is that the logical partitions can share the same
physical network adapters that will decrease the required physical adapters on
the system. Virtual Ethernet is a special network adapter type that does not
require physical adapters at all. Instead, it is provided through PHYP as a fast
way of communication between logical partitions. You can, for instance, set up
60
DB2 Virtualization
WebSphere Application Server (WAS) to connect to the DB2 server through a
virtual Ethernet.
Considering the performance, there are no major differences between the
various types of network options. You should choose the appropriate network
type based on your hardware and overall system setup.
Disk I/O type
Choosing the correct disk I/O type is the most critical decision that you must
make. It effects the overall database performance significantly and is also one of
the hardest to change later once the setup is complete. Though there are
multiple types of options to select from, since disk I/O is critical, it limits the
choices.
For the OS you should choose the disk type as you would choose any other type
of logical partition. In this book we concentrate on choosing a storage option for
DB2 use. Pay attention while choosing a storage option for the data and
transaction logs. The same best practises for storage hold true on the virtualized
environments as they do on the physical servers with a few exceptions.
First of all, you must choose between the locally attached storage and the virtual
storage. Although the virtualized storage is easier to manage, it comes with a
cost. There is always some overhead when storage is virtualized. On some
systems and workloads this overhead may be acceptable. However, many
systems and workloads require optimal disk I/O, for instance, database server.
In general, DAS is not fast enough for the database servers. SAN disk is a better
choice for the database servers. SAN disks have large disk caches and can also
be easily maintained. Also, they can be configured to use the available RAID
levels. The SAN systems can be used through VIOS or as a local attached
storage.
For optimal performance, we recommend the locally attached storage. When I/O
through VIOS can be used without effecting I/O performance, this option can be
chosen. Choose the VIOS-managed storage only if the I/O performance is not
affected by the virtualization layer. For the reset of database storage planning,
follow the best practices discussed in Best Practises: Database Storage at:
http://www.ibm.com/developerworks/data/bestpractices/databasestorage/
Chapter 3. Power Systems and PowerVM
61
Best practises that we would like to highlight are:
 Think about real spindles, not just storage space. Most storage specialists are
happy to give DBA the amount of storage space required, but not the number
of spindles needed.
 Have dedicated LUNs and file systems. File systems should be created on
their own LUNs, not disk partitions.
 Stripe at most in two places. For instance, if you are using multiple storage
paths for your tablespace containers, you can stripe your storage on the SAN
system or at the OS level, but not on both.
 Separate DB2 transaction logs and data. You must have logs and data on
their own disks, not just on their own disk partitions.
 Use file systems instead of raw devices for LUNs—one file system per LUN.
Raw devices might offer a slight performance boost in special cases, but the
price, in addition to complicating database maintenance, is too high.
 Use the NO FILE SYSTEM CACHING clause. This option prevents double
buffering and is highly recommended.
 Use DB2 automatic storage to stripe everything everywhere. Automatic
storage offers optimum performance and ease of use and maintenance. In
case you need more I/O, it is as simple as adding a storage path.
 Do not hand-tune the NUM_IOCLEANERS, NUM_IOSERVERS, and
PREFETCHSIZE configuration parameters. With dynamic logical partitioning,
setting these database parameters to AUTOMATIC is even more important
than on the non-virtualized environments.
Virtual I/O Server
You can have a Power Systems environment without VIOS, but this would be a
special case. Most systems have at least one VIOS. To provide high availability,
there must be at least two VIOSs. To achieve the most from your system, define
your VIOS as an uncapped shared partition and its tune uncapped weight value
properly.
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DB2 Virtualization
For more information about setting up VIOS refer to the following resources:
 PowerVM Virtualization on IBM System p: Introduction and Configuration
Fourth Edition, SG24-7940, available at:
http://www.redbooks.ibm.com/abstracts/sg247940.html
 IBM PowerVM Virtualization Managing and Monitoring, SG24-7590,
available at:
http://www.redbooks.ibm.com/abstracts/sg247590.html
 VIOS in IBM System Information Center at:
http://publib.boulder.ibm.com/infocenter/systems/index.jsp?topic=/com.ibm.aix
.security/doc/security/capp_vios.htm&tocNode=toc:front/front.cmb/0/0/11/0/0/2
/11/13/
3.3 DB2 setup and configuration
Now that the LPAR is set up, it is time to discuss how to set up the DB2
environment. Most DBAs may not realize that they are running on a virtualized
environment when DB2 is with AIX or pLinux on a Power Systems server and
thus neglect tuning and configuring DB2 to take the benefits that virtualization
has offer on a Power Systems LPAR.
In this section we discuss the following topics:
 Installing and setting up DB2
– Setting up storage
– Setting DB2 configuration parameters
 Configuration example
 Best practices
3.3.1 Installing and setting up DB2
In this section we discuss DB2 installation and initial configuration. We especially
concentrate on how to configure DB2 detecting the changes in a dynamic Power
Systems environment.
DB2 installation
Install DB2 on Power Systems logical partition as you would install it on a
non-virtualized environment. On AIX, DB2 is installed under the /opt file system,
which is usually on its own logical volume under the rootvg volume group. On
pLinux there are no differences either. DB2 is installed under the /opt file system
Chapter 3. Power Systems and PowerVM
63
on its own subdirectory with no changes to the default for the installation.
Virtualization does not effect the installation type or the options.
Setting up DB2
DB2 will benefit from the autonomic features, Self Tuning Memory Manager
(STMM) and automatic storage, that have evolved especially in the DB2
Version 9 family. For instance, when dynamically changing processor or memory
for a logical partition, DB2 is able to detect the changes dynamically online
without the need to restart the instance. DB2 will make the necessary
adjustments for the database heap and the buffer pools as well as for instance
I/O servers if this will improve DB2 performance and increase transaction
throughput.
Setting up storage
You should set up your transaction logs and data on separate file systems and,
ideally, on external storage systems on their own dedicated LUNs. In our
examples we set up transaction logs under the /db2logs directory and data
under /db2data on different subdirectories. These file systems are located in a
SAN system on their own dedicated LUNs. We defined our database paths as
shown in Example 3-1 using the database creation clause.
Example 3-1 Database creation clause
CREATE DATABASE virtdb AUTOMATIC STORAGE YES ON /db2data/data1, /db2data/data2,
/db2data/data3, /db2data/data4 DBPATH ON /db2data/data1
As you see from the above example, we use automatic storage. This significantly
reduces time spent on maintenance when there is a need to add storage paths to
our database. Automatic storage provides optimal performance as well, so it is
an ideal choice for storage type.
When you need more storage space or I/O you will need to provide additional
LUNs from your SAN system and then make them available to your OS. After this
you will be able to add the new storage path for your database environment. This
increase in storage paths for your database table spaces will not only increase
the amount of storage, but I/O capacity as well.
Example 3-2 shows the command for adding two additional storage paths to our
database. Ideally, each storage path should be equal in size and lay on its own
file system under dedicated LUNs.
Example 3-2 Adding storage path
ALTER DB virtdb ADD STORAGE PATH /db2data/data5, /db2data/data6
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DB2 Virtualization
When the I/O capacity has increased, you may need more CPU capacity in order
to handle the increased I/O. For an uncapped shared processor logical partition
this would not be a problem as long as there is enough CPU capacity in the
shared processor pool. If the increase in the needed CPU capacity will be
permanent, you should consider increasing the entitled processor capacity for
the database logical partition. With dynamic logical partitioning this can be
achieved without any effect to service. You just must change the value of the
desired processor units for the LPAR.
As discussed earlier, for a Power Systems server environment you must choose
between the virtualized storage and the locally attached storage. Although the
virtualized storage provides easier maintenance, it has a slight overhead. On
most systems this overhead is not noticeable, so we are able to take advantage
of the benefits for easier maintenance when using virtual storage. VIOS makes it
easier to add more storage to your system without a service break. With more
than one virtual server, you are always able to add physical adapters and SAN
systems to your environment without service breaks on your production
environment. This ability to provide additional storage and I/O resources without
service downtime, combined with the ease of use and maintenance of DB2
automatic storage, makes Power Systems environments ideal for dynamic
computing environments with dynamic resource needs.
Setting DB2 configuration parameters
Take advantage of the DB2 9 autonomic computing features on your virtualized
environment to be able to optimize the system performance with dynamic
changes. By utilizing DB2 autonomics, your system is capable of adopting
changes in the computing environment automatically. For instance, over time the
number of users accessing the system might increase. On an OLTP system, this
is usually most noticeable through the increase in reads and writes in the
database usage. When the amount of data and the number of user accesses
grow on the system, you might need larger buffer pools and more disk space and
disk I/O. We have discussed how to handle the demand changing for storage and
I/O. In this section we concentrate on providing information about how to benefit
from DB2 autonomic features combined with Power Systems dynamic
capabilities.
You should check that the configuration parameters on both the instance and the
database level are set properly so that DB2 can automatically reallocate the
resources such as heaps when there are changes in system resources. Since
the processing capabilities of a uncapped shared processor partition will change
dynamically depending on the need for the computing resources, you should pay
special attention to those CPU-bound configuration parameters.
Buffer pools and other memory-related DB2 parameters are automatically
re-sized by DB2 when you have STMM enabled and when you have set the
Chapter 3. Power Systems and PowerVM
65
buffer pool sizes as AUTOMATIC. This makes it possible to dynamically add
system memory to the database LPAR. DB2 will notice this change in memory
resources and tune the database memory, the buffer pools, and other
memory-related parameters correspondingly.
Follow general guidelines and best practices about on how to tune your DB2
configuration parameters.
3.3.2 Configuration example
To show you how the DB2 autonomic computing features work in a virtualized
environment, we build a test environment. The tests that we run on our test
environment are not meant to be an example of how to build or set up a real-life
production environment. The purpose of setting up the environment is to show
how the autonomic DB2 features react to the dynamic changes in a virtualized
environment.
Setting up Power Systems and LPARs
We set up a Power Systems environment on an 8-way POWER5 server with
16 GB memory, as illustrated in Figure 3-3.
Figure 3-3 Test environment setup
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DB2 Virtualization
We create a very basic environment with only three LPARs. One of the LPARs is
used as the VIOS. All of our LPARs are shared processor partitions in uncapped
mode. Table 3-1 shows the memory and CPU settings.
Table 3-1 LPAR setup
System
name
Minimum
CPU
Desired
CPU
Maximum
CPU
Minimum
memory
Desired
memory
Maximum
memory
VIOS
0.5
0.4
1.0
512 MB
1.0 GB
2.0 GB
AIX01
0.5
1.0
2.0
1.0 GB
1.0 GB
2.0 GB
AIX02
0.5
1.0
6.0
1.0 GB
1.0 GB
8.0 GB
Storage setup
We run all of our tests with AIX02 running DB2 9.7 Enterprise Server Edition. We
configure the database to use automatic storage on two file systems located on
the external storage device locally attached to our system. Example 3-3 shows
the file system setup—two file systems capable of storing 20 GB data together
and one 10 GB file system for the database transaction logs.
Example 3-3 Storage setup for database data and logs
$ df -g | egrep "Files|data|logs"
Filesystem
GB blocks
Free %Used
/dev/datalv1
10.00
10.00
1%
/dev/datalv2
10.00
10.00
1%
/dev/logslv
10.00
10.00
1%
Iused %Iused Mounted on
4
1% /data/data1
4
1% /data/data2
4
1% /data/logs
To create the database on the newly created file systems we use the command
shown in Example 3-4.
Example 3-4 Creating the database
CREATE DATABASE testdb AUTOMATIC STORAGE YES ON /data/data1, /data/data2 DBPATH
ON /data/data1 USING CODESET ISO8859-1 TERRITORY US COLLATE USING IDENTITY;
Next we create the tables under USERSPACE1 and populate them with test data.
All the tables are created with compression enabled by using the COMPRESS
YES option. This not only saves our storage costs, but also keeps the
requirements for I/O and memory smaller due to the row compression. Note that,
in general, it is not a good idea to create all the tables with the COMPRESS YES
option, unless you know that all the tables will benefit from the compression. We
are sure that all our test tables can benefit from the compression. Therefore, we
use the COMPRESS YES option in all of them.
Chapter 3. Power Systems and PowerVM
67
DB2 configuration
When creating a database on DB 9.7, the autonomic features, STMM and
automatic storage feature, are enabled by default unless explicitly defined
otherwise. It is a good practice to verify these settings, especially for the migrated
databases. Table 3-2 lists how our database, TESTDB, parameters are set.
Table 3-2 Data parameters for the TESTDB database
Parameter no.
Parameter name
Value
1.
SELF_TUNING_MEM
ON
2.
DATABASE_MEMORY
AUTOMATIC
3.
LOCKLIST
AUTOMATIC
4.
MAXLOCKS
AUTOMATIC
5.
PCKCACHESZ
AUTOMATIC
6.
SHEAPTHRES_SHR
AUTOMATIC
7.
SORTHEAP
AUTOMATIC
8.
DBHEAP
AUTOMATIC
9.
STMTHEAP
AUTOMATIC
10.
APPLHEAPSZ
AUTOMATIC
11.
APPL_MEMORY
AUTOMATIC
12.
STAT_HEAP_SZ
AUTOMATIC
13.
NUM_IOCLEANERS
AUTOMATIC
14.
NUM_IOSERVERS
AUTOMATIC
15.
DFT_PREFETCH_SZ
AUTOMATIC
16.
MAXAPPLS
AUTOMATIC
17.
AVG_APPLS
AUTOMATIC
Parameters 1–12 are memory related and have a dependency on how much the
physical memory on the LPAR is available for the database. Parameters 13 to 15
will be effected by changes in the processing capacity. The remaining
parameters, 16 and 17, will be calculated based on both memory and processing
capacity.
To simplify the test environment, we have only one user table space for all tables.
This table space has one buffer pool, IBMDEFAULTBP. We verify the buffer pool
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DB2 Virtualization
setting to ensure that DB2 STMM can dynamically adjust the buffer pool when
the memory requirements or available memory changes. Example 3-5 shows
that the buffer pool size is set to -2, which stands for AUTOMATIC. On DB2 9.7,
this is the default setting.
Example 3-5 Checking buffer pool size
$ db2 "SELECT SUBSTR(BPNAME,1,12) AS BUFFERPOOL, NPAGES AS SIZE FROM
SYSCAT.BUFFERPOOLS"
BUFFERPOOL
SIZE
------------ ----------IBMDEFAULTBP
-2
1 record(s) selected.
Running the test
Now our test database setup is complete. We run three tests to check how
dynamic changes in memory capacity affect DB2 performance. We begin with
only 1 GB memory. This amount of memory is not much nowadays, but it will be
interesting to see how STMM behaves with this little memory. We run our tests
that simulate an OLTP workload for four and half hours. This is the first point to
check how the system is performing. We check the following values:
 Computed size for the following database configuration parameters:
–
–
–
–
DATABASE_MEMORY
LOCKLIST
SORTHEAP
DBHEAP
 Statistics and values for the buffer pool, IBMDEFAULTBP:
– Computed size for number of pages
– Index and data hit ratio
 Average OS CPU utilization including:
– User CPU
– System CPU
– I/O wait
We continue on increasing the amount of memory from 1 GB to 2 GB and keep
the OLTP load test running for the next four hours, which is our next check point.
The last step is to double the memory dynamically once again and record the
final numbers.
Chapter 3. Power Systems and PowerVM
69
After we started the test, we did not change anything on DB2. STMM took care of
all the tuning. Figure 3-4 shows the database performance changes during the
test. The transactions per second (TPS) increased significantly during the test.
The average TPS was 80 with 1 GB memory. By increasing the memory to 2 GB
we received a 91% increase in average TPS. When doubling the memory once
again, we received another 8% increase on average TPS. The later number
could be better though since the increase in memory was noticeable.
Figure 3-4 Increase in transaction rate per second
Let us see how we do with other numbers. Figure 3-5 shows the changes in
buffer pool size, hitratio for IBMDEFAULTBP, and other memory-related DB2
parameters. At the start of the test the hitratio for buffer pool IBMDEFAULTBP
was 81.28%. When changing the memory from 2 GB to
4 GB we did not get a better hitratio. It actually went down a bit from 90.59% to
90.47%. There are also no significant changes in DB2 parameters that were set
to be taken care of by STMM.
Figure 3-5 DB2 memory-related parameters
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DB2 Virtualization
Now we check the system performance in total. When the memory is increased
from 2 GB to 4 GB, we obtain an additional good 8% TPS increase with the
fine-tuning automatically performed by DB2. The load test used to test the
system performance reads data extensively. Since there was no increase in
buffer pool hitratio, it implies that it has reached the optimum level. On the other
hand, 90% buffer pool hitratio implies that we must read from disk 10% of all the
data that we are accessing.
Figure 3-6 reveals where is our bottle neck. Although we have been able to utilize
more CPU while increasing the memory, we are still waiting on I/O a lot. This I/O
wait did not significantly go any lower when memory was increased. This was
expected, since the load test that we use reads data extensively. To get better
performance, we could add storage paths on the dedicated LUNs to our
database. This would increase the I/O, but only if the amount of data would
increase enough over time to start spreading into the newly created storage path
containers. Just adding storage paths to the system that already has slow I/O
does not necessarily make the system any faster. Adding storage paths will help
on the system where I/O is becoming the bottleneck due to the increase in data.
In our case, the easiest to resolve the I/O wait issue would be to recreate the
database with more storage paths on dedicated LUNs with enough I/O capacity.
Figure 3-6 Operating system utilization
Looking at our physical CPU usage, we notice that we are using at maximum of
60% of our entitled capacity. Since we have a total of five unused processors in
our shared processor pool, we should reach a much higher CPU usage rate than
the entitled capacity, but not until the current I/O bottle neck is removed.
Chapter 3. Power Systems and PowerVM
71
When building our test system we used two file systems for data. These file
systems are not located on a dedicated LUN of their own. Instead, the file
systems share the same LUN, which partially explains the I/O bound result. If this
system was supposed to go into production we would need to get a more
efficient I/O solution.
The test results were extremely encouraging considering how much of a
performance increase we were able to achieve by letting DB2 take care of the
tuning. Even when DB2 just slightly fine-tuned the memory usage, we were able
to achieve 8% performance increase without an manual effort. This achievement
resulted from relatively small changes in memory parameters by DB2. An 8%
performance increase would be a very challenging task even for a very
experienced DBA, especially under the condition that the overall DB2 memory
usage is practically not increased at all.
By utilizing Power Systems dynamic logical partitioning capabilities with DB2
autonomics, we were able to achieve significant performance increase in just a
few hours by letting DB2 take care of tuning. The overall performance increase
was 119%, which is not bad at all.
3.4 Conclusions
By setting up a test environment, running tests, and following the DB2 best
practises, we have come to the following conclusions:
 You should place the DB2 server in an uncapped shared processor partition.
This gives you the ability to fully utilize system resources including usage
peaks and unpredictable workloads.
 For maximum performance, use fast SAN disks attached locally to the LPAR.
Use dedicated LUNs for the file systems. Utilize the DB2 automatic storage
feature to stripe over the file systems. As observed in our tests, I/O can
become the bottleneck very easily. Remember that whatever choice you make
for your I/O and storage during the planning phase, it is the hardest to change
later.
 Use DB2 autonomics to fully utilize dynamic changes in the Power Systems
environment. To be able to detect the changes in a dynamic operating
environment and act as required, use DB2 STMM and automatic storage
features. This will guarantee that DB2 will tune itself to reflect the changes
that it detects on both workloads and the operating environment.
 For the network interface choose among SEA, Virtual Ethernet, and locally
attached network adapter. There is no benefit, performance-wise, to attach
network adapters locally. You can select any virtualized network solution or
use locally attached network adapters.
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DB2 Virtualization
 Utilize VIOS for easier maintenance and efficiency. Although you might need
to use locally attached storage, you are still able to benefit from virtualized
I/O. To be able to fully maximize the system utilization, install your VIOS as an
uncapped shared processor partition and tune uncapped weight properly.
Chapter 3. Power Systems and PowerVM
73
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DB2 Virtualization
4
Chapter 4.
VMware vSphere
VMware is the market leader in virtualization technologies for x86 platforms.
VMware vSphere is a cloud operating system. DB2 is capable of utilizing and
taking full benefit of the virtualization features that VMware virtualization
solutions have to offer.
In this chapter we discuss VMware virtualization technologies and features. We
discuss how to set up and build a VMware environment including VMware
ESX/ESXi Servers, vCenter Servers, vSphere Client, and virtual machines
running DB2. We provide useful information about how to set up your DB2 to get
most out of a VMware virtualized environment. We focus on the following topics:




VMware architecture
Setting up the VMware virtualized environment (vSphere)
VMware virtual machine installation
Configuring DB2 for VMware
© Copyright IBM Corp. 2009. All rights reserved.
75
4.1 Architecture
In this section we describe the high-level architecture of VMware vSphere and
some of its components. We focus on the most essential components for setting
up a virtualized environment for DB2.
4.1.1 vSphere
VMware vSphere is a suite of virtualization applications. vSphere provides
virtualization technologies for running multiple operating systems on a single
physical machine simultaneously. It can reclaim idle resources and balance
workloads across multiple physical machines. vSphere is able to move a running
virtual machine to another virtual machine without a service break. This feature
provides constant system availability even when a hardware failure is
encountered. It is also helpful for scheduled maintenance.
VMware vSphere includes the following major components:







76
ESX
VMware file system (VMFS)
vCenter
Distributed Resource Scheduler (DRS)
VMware High Availability (HA)
VMware Fault Tolerance
VMotion
DB2 Virtualization
These major components enable vSphere to provide both infrastructure services
and application services. Figure 4-1 illustrates an overall VMware architecture
and how vSphere fits into it. The infrastructure services of VMware vSphere offer
the manageability for the underlying hardware. These services virtualize the
computing, storage, and network devices. The application services of VMware
vSphere include services for high availability, security, and scalability in the
virtualized environments. The entire vSphere environment is controlled by the
VMware vCenter suite. This is a management suite that can easily administer
even the very large virtualized environments.
Figure 4-1 vSphere architecture (Copyright © 2009 VMware, Inc. All rights reserved.)
4.1.2 ESX
ESX uses a bare-metal hypervisor that allows multiple virtual machines to run
simultaneously on the same physical server. The ESX hypervisor called
VMkernel is a proprietary, kernel-optimized high-performance component for
running virtual machines. The ESX service console is used only to provide a
management interface to the VMkernel. The service console is a cut-down,
secure version of Linux. The service console is scheduled to use hardware
resources in a manner similar to normal virtual machines.
Chapter 4. VMware vSphere
77
ESX 4 and ESXi are both bare-metal hypervisors that partition physical servers
into multiple virtual machines. The difference is that ESXi does not use a Linux
service console as a management interface. ESXi is managed by VMware
vCenter, using an embedded hardware agent. Figure 4-2 depicts this
architecture.
Figure 4-2 ESX architecture (Copyright © 2009 VMware, Inc. All rights reserved.)
All hardware components are virtualized and are under control of ESX. This
allows VMware to provide advanced resource management features for ESX.
The important features regarding DB2 are:
 Resource management for virtual machines allows establishment of
minimum, maximum, and proportional resource shares for CPU, memory,
disk, and network bandwidth. Modifications are allowed while virtual
machines are running.
 Intelligent CPU virtualization provides a mechanism to execute virtual
machine processes with intelligent process scheduling and load balancing
across all available CPUs on the physical host.
 Network traffic shaping ensures that critical virtual machines receive priority
access to network bandwidth. Network traffic from virtual machines can be
prioritized.
 Storage I/O traffic prioritization ensures that critical virtual machines receive
priority access to storage devices by prioritizing I/O traffic.
System requirements
ESX is compatible with a variety of systems, I/O devices, operating systems, and
storage arrays. For the information about the supported systems for different
versions of ESX, refer to:
http://www.vmware.com/resources/compatibility/search.php
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DB2 Virtualization
Supported operating systems
VMware supports many different Microsoft Windows versions and Linux
implementations. DB2 also supports different versions for both types of operating
systems. To build a DB2 sever on a VMware virtualized environment, an
operating system version supported by both DB2 and ESX is required. To find the
operating systems supported by both DB2 and ESX, refer to the following Web
sites:
 DB2 and virtualization: supported environments
http://www.ibm.com/developerworks/wikis/display/im/DB2%20Virtualization%20
Support
 VMware: supported operating systems
http://www.vmware.com/pdf/GuestOS_guide.pdf
 DB2 9.7 for Linux: supported environments
http://www.ibm.com/developerworks/wikis/display/im/DB2+9.7+for+Linux+-+
Supported+Environments
 Installation requirements for DB2 database products
http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/index.jsp?topic=/com.ibm
.db2.luw.qb.server.doc/doc/r0025127.html
Chapter 4. VMware vSphere
79
4.1.3 VMFS
VMware vStorage is a cluster file system that allows multiple instances of ESX to
read and write to the same storage, concurrently. By storing the entire virtual
machine state in a central location, VMFS enables you to simplify virtual machine
provisioning and administration. Through these capabilities VMFS provides easy
support for live migration of running virtual machines or automatic restart of a
failed virtual machine on a separate physical server. Figure 4-3 depicts the
VMFS usage.
Figure 4-3 VMFS (Copyright © 2009 VMware, Inc. All rights reserved.)
Virtual machines have virtual disks that are seen by the guest operating system
(OS) as physical disks. These virtual disks are actually files under VMFS file
systems. VMFS can be created under any storage device, which can be either
internal or external disk as well as Network Attached Storage (NAS) or iSCSI
disk. These disk devices, which are used to store virtual machine data and virtual
disks under VMFS file systems, are called datastores. Typically, SAN solutions
offer the best performance and features to be used as datastores.
4.1.4 vCenter
VMware vCenter Server is a powerful application built to manage VMware’s
virtual infrastructure, vSphere. Through the vCenter you can centrally manage
hundreds of ESX hosts, and each ESX host can have 10 - 50 virtual machines.
vCenter delivers the highest levels of efficiency, reliability, and security required
to manage a virtualized IT environment of any size.
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DB2 Virtualization
vCenter is designed to aggregate physical hardware (networking, storage,
memory, and CPU) and manage it as a collection of resources that can be
allocated dynamically on business needs. Figure 4-4 provides an overview of the
vCenter components.
Figure 4-4 vCenter overview
The vCenter management information is stored in a dedicated vCenter database
to store and organize all its information about the vSphere management
environment. The database can be installed on the same machine where the
vCenter is installed or on a dedicated database machine. The data in the vCenter
database can be divided into three broad categories:
 Inventory
This includes host and virtual machine configurations, resources, and virtual
machine inventory, user permissions, and roles. The inventory information in
vCenter stores extra host information.
 Alarms and events
This includes notifications that are triggered based on virtual machine state
changes. The alarm and event data is store indefinitely in the vCenter
database.
 Performance statistics
This includes the performance and resource utilization statistics for
datacenter elements, such as hosts, clusters, resource pools, and virtual
machines. vCenter provides configurable settings to control how performance
Chapter 4. VMware vSphere
81
statistics are collected across the VMware Infrastructure environment.
Performance statistics comprise up to 90% of the vCenter database size and
therefore are the primary factor in performance and scalability of the vCenter
database.
4.1.5 VMware High Availability (HA)
VMware HA provides high availability for the hosts running on the virtual
machines. If the host server on the VMware cluster goes down due to a hardware
failure or any other reason, all of the virtual machines running on it will go down
as well. With VMware HA, if one host fails, the virtual machines will be booted
automatically on a different host within the same VMware cluster. The virtual
machine will loose only the in-memory state of the virtual machine and the
service break will be minimal. VMware HA does not require any additional cluster
software to be configured on the virtual machines, which makes it easy to deploy.
4.1.6 VMware Fault Tolerance
VMware Fault Tolerance provides continuous availability for your virtual servers
and applications by utilizing VMware vLockstep technology. With the VMware
Fault Tolerance you have a shadow copy of your running virtual machine, which
is able to take place in case of hardware failure. VMware Fault Tolerance is easy
to deploy for the existing VMware HA clusters and it does not require the
traditional HA capabilities from your software running on virtual machine.
4.1.7 Distributed Resource Scheduler
The Distributed Resource Scheduler provides the feature to control resource
allocation across hosts and resource pools. Therefore, it collects resource usage
information for all the hosts and virtual machines in a cluster and generates
recommendations for virtual machine placement. Depending on the configured
DRS automation level, those recommendations can be applied manually or
automatically. The recommendations can be applied during start of a virtual
machine or during runtime.
Initial placement
DRS makes recommendations for the placement of a virtual machine or starts it
automatically on the recommended host.
Load balancing
At runtime, DRS either uses VMotion to automatically migrate virtual machines or
provides recommendations for virtual machine migrations.
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DB2 Virtualization
4.1.8 VMotion
VMotion enables you to migrate a virtual machine and its disk files from one
machine to another while the virtual machine is running. You can choose to place
the virtual machine and all its disks in a single location, or select separate
locations for the virtual machine configuration file and each virtual disk.
With VMotion you are able to upgrade VMware Infrastructure without any
downtime of the virtual machines. You can then use Storage VMotion to migrate
virtual machines back to the original datastore without service interruption.
VMotion is also very useful during storage maintenance windows. You can use it
to redistribute your storage loads as well to achieve better balance capacity or
performance.
4.2 VMware setup
In this section discuss how to set up a VMware virtual environment that can also
be referred as vSphere. We discuss general concepts and setup steps. We focus
on how to set up vSphere so that DB2 servers are able to get most out of it. We
discuss the following items:





Planning and setting up a VMware virtualized environment
Installing and setting up VMware ESX/ESXi servers
Installing and setting up vCenter Servers
Configuring a vSphere through vSphere Client
Considerations on disk storage and choosing from different options
VMware virtual infrastructure planning
Before you start installing and setting up your VMware environment, you should
carefully plan your environment. You must think properly about how much and
what kind of hardware you need. Another decision to make is what kind software
is required for managing and maintaining your VMware virtualized environment.
Stand-alone solution
If you have a small environment or you are just exploring VMware capabilities,
you might get along with just one stand-alone VMware ESX/ESXi Server.
Normally, you would want to have more than one VMware ESX/ESXi Server to
be able to provide high availability for your virtualized servers. After all, since you
are supposed to run more than one virtualized server on top of your VMware
ESX/ESXi Server, you do not want all of them to go down in case of hardware
failure.
Chapter 4. VMware vSphere
83
To be able to provide continuous service you need at least two VMware
ESX/ESXi servers. This way you can ensure that in case of failure you are able to
move your virtual servers to another VMware ESX/ESXi Server. Moving the
virtual machines from one server to another can be done either automatically or
manually. Depending on your requirements, this can be done in many different
ways.
For instance, DB2 can provide continuous service by utilizing High Availability
Disaster Recovery (HADR) technology. This solution does not require external
storage and can be implemented through two stand-alone VMware ESX/ESXi
Servers both running one the same physical DB2 server. There are similar
clustering solutions with other server software. Some of these solutions require
external shared storage, but for HADR external shared storage is not required.
VMware vSphere
To be able to utilize centralized maintenance technologies that VMware has to
offer and to fully benefit from VMware HA solutions, you probably want to deploy
VMware vCenter. With vCenter your VMware virtualized environment will
eventually extend to what VMware calls vSphere. With stand-alone VMware
ESX/ESXi Servers your virtual environment will be on some level very much like
traditional non-virtualized environments. Although you can benefit from easy
server deployments and better hardware utilization by virtualization, you are still
lacking many of the superior virtualization features. Once you have moved to a
full vSphere environment, you can benefit from the following VMware
virtualization features:
 VMware HA: With VMware HA you are able to provide DB2 high availability
without deploying any native DB2 HA solutions. Note that VMware HA does
not automatically provide continuous service for your applications.
 VMware Fault Tolerance: With VMware Fault Tolerance you are able to
provide continuous service without deploying traditional HA solutions.
 VMware DRS: With DRS you are able make sure that your workloads will get
the most out of your hardware.
 VMware VMotion: With VMotion you are able to do, for instance, hardware
upgrades without service breaks by migrating your virtual server from one
physical server to another during the upgrade.
 VMware Storage VMotion: SVMotion enables you to move your workloads
from a storage system to another without out service breaks.
Although you are able to achieve most of the benefits that these features have to
offer by using DB2 HA technologies, you still might want to consider taking
advantage of VMware vSphere. These VMware vSphere features, which are
enabled in full vSphere solution, offer even more flexibility if combining with DB2
technologies.
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DB2 Virtualization
You do not have to upgrade to a full vSphere environment at once. You can start
with a stand-alone VMware ESX/ESXi Server and gradually extend your
virtualized infrastructure to a full VMware vSphere environment as needed.
VMware vSphere is a full package of virtualization features and technologies.
VMware vSphere consists of the following software and hardware components:
 One or more VMware ESX/ESXi Servers
 One or more vCenter servers
 Database server
 The underlying hardware that consists of:
– The physical servers and peripherals connected to them.
– Storage systems connected to the host servers. These can consist of
either external or internal storage solutions, or both.
The number of VMware ESX/ESXi Servers required is dependant on the
hardware that you choose to use and how many virtual servers you are going to
deploy on your environment. To be able to get the most out of the VMware
vSphere, you need at least one vCenter Server. You do not necessarily need
additional software for the vCenter Server servers since you can run these on the
VMware virtual machines as well.
We highly recommend having external SAN solutions. SAN technologies offer
the ability to provide a flexible storage solution with very fast I/O and database
servers are usually dependent on fast storage. Also, many of the vSphere
features such as VMotion, Storage VMotion, VMware HA, and DRS are
dependent on external storage.
VMware ESX/ESXi installation and setup
There are three options that you can choose from for your VMware ESX/ESXi
server:
 VMware ESXi Embedded Edition: This option is available if you use the
hardware that VMware ESXi embedded in the hardware firmware.
 VMware ESXi installable Edition: If you choose this option, you can use any
supported hardware and perform the VMware ESXi installation.
 VMware ESX Edition: This option has a slightly larger memory foot print, but it
does include VMware Service Console, which you might want to have for the
configuration and maintenance tasks.
Refer to the VMware documentation for hardware requirements as well as for
how to install and set up your VMware ESX/ESXi servers.
Chapter 4. VMware vSphere
85
vCenter Server installation and setup
vCenter Server acts as a focal point for a vSphere environment. You are able to
configure and maintain the entire vSphere environment through vCenter. To store
and access vSphere configuration data vCenter requires a supported database.
vCenter Server can be installed both on physical and on virtual hardware. The
database server can be installed on the same virtual or physical machine as
vCenter, or you can dedicate additional hardware for it.
Before starting the vCenter Server installation you must check the hardware
requirements. Up-to-date hardware requirements, including installation and
setup guides, are available at:
http://www.vmware.com/support/pubs/vs_pubs.html
You also must decide what database solution you are going to use with your
environment. vCenter Server is bundled with Microsoft SQL Server 2005
Express database, which allows you to set up to five hosts and 50 virtual
machines. vCenter server supports other database engines including DB2 for
larger deployments. As for vCenter Servers, you do not necessarily need
additional hardware for the database server. You can run it on a virtual server.
vSphere Client
VMware vSphere Client can be installed on a workstation, mobile computer, or
server depending on your needs. Check the up-to-date data for hardware and
software requirements for vSphere Client from VMware documentation. By using
one vCenter Client you are able to connect to one or more vCenter Servers. You
can also have more than one vSphere Clients installed to configure and manage
your vSphere environment.
Managing vSphere
Once you have your environment set up you are ready to start configuring your
VMware vSphere. Through vSphere Client you are able to:
 Create data centers. You can define a data center, for example, based on the
geographic location of your servers.
 Add or remove ESX/ESXi hosts. You are able to add or remove hosts to and
from your vSphere. Hosts must be added under a certain data center.
 Create and manage clusters. You are able to add and modify host clusters
under the data centers. The host clusters must be able to utilize vSphere
features such VMotion, VMware HA, and DRS.
 Create and manage resource pools. You can manage your workloads with
resource pools. Use vSphere Client to manage the resource pools.
 Create and manage virtual machines. The vSphere Client is the focal point for
creating and managing the virtual hosts. You are able to change resource
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DB2 Virtualization
settings and get information about virtual machine performance through the
vSphere Client.
 Manage and configure the datastores. You are able to deploy and manage
datastores. You are able to configure the storage paths for datastores. If you
need to upload, download, or browse files and folders on your datastores, use
the vSphere Client.
 Monitor host and virtual machine performance. You can use the vSphere
Client to view and create performance graphs about the hardware resource
usage including I/O, memory, and CPU on both the hosts and guests.
vSphere Client offers all the tools that you need to configure and manage your
vSphere. vSphere Client is a good example of how virtualization can make
managing and monitoring a large number of servers much easier than it would
be on a traditional physical server environment.
You are able to monitor how the servers use the I/O, CPU, and memory
resources. If there is a need for more I/O, CPU, or memory, you are able to
re-allocate these resources among the servers. For example, if you observe that
one server has a lot of idle memory, you can re-assign the memory for other
servers that might be lacking it.
Setting up or creating a virtual machine on a properly designed vSphere
simplifies the tasks remarkably if compared with similar tasks required on a
physical environment. You are able to create a virtual machine in minutes. You
can utilize VMware templates to make the operating system deployment much
easier than it would be normally. If there is additional software required to be
installed for all the servers due to company policy or other issues, with templates
you get the ready-build operating systems containing all the required software
pre-installed and configured.
Considerations on storage
Storage plays a critical role for the performance of a database system. DB2 is no
exception. You must design and build the storage in such a way that DB2 will
have enough I/O resources to manage the I/O bound workloads. A good way is to
utilize the SAN systems with properly configured arrays. Just as the best
practices suggest, you should think about the number of spindles, not just how
much storage space is required. The more spindles you have in your RAID array,
the more I/O they can generate.
Chapter 4. VMware vSphere
87
Failover configuration
You should design your system to have the failover capabilities in case of
hardware failures. Figure 4-5 shows one example of a SAN failover configuration.
Figure 4-5 A SAN failover configuration
In general, a SAN solution with a failover configuration consists of the following
components:
 The SAN box itself.
 The disks in the SAN.
 A minimum of two controllers in the SAN. All of them have at least two Fibre
Channel ports. SAN controllers can operate in active/passive or active/active
mode. With active/passive mode, all disk arrays are accessed through the
active controller. Load balancing is not possible on active/passive mode. With
active/active mode both controllers can be used simultaneously. All our
examples assume the use of active/active mode.
 The host machine typically has at least two Fibre Channel host bus adapters
(HBAs).
 Two Fibre Channel switches. In our example we have connected the Fibre
Channel switches to both controllers. With this configuration, both HBAs on
the host can access the LUN through both SAN controllers.
We use a lab configuration similar to this one for our discussion in this chapter.
When a storage administrator configures the SAN, he first creates a RAID array.
In our lab, we have five disks. The plan is to configure the RAID array on these
five disks—four for data and one for parity, a normal RAID-5 4+1 configuration.
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DB2 Virtualization
Using the SAN configuration software, we can assign the logical unit number
(LUN) on the RAID array and present the LUNs to the host machine so that the
host machine is able to see the LUNs as physical disks. Our host machine has
two Fibre Channel cards, which are connected to the SAN box controllers
through the Fibre Channel switches. This makes a total of four paths to the LUNs,
where two of them are controlled by the host machine through the Fibre Channel
cards. Note that without correct multi-path Fibre Channel drivers, the host
machine would see each LUN as four physical disks. By using supported
hardware we ensure that the host machine will see correctly only one disk per
LUN and can take advantage of multi-path drivers.
This simple failover configuration provides us a certain level of hardware failure
protection. We can lose one Fibre Channel HBA on the host machine, one Fibre
Channel switch, or one Fibre Channel controller on the SAN box without service
interruption. The Fibre Channel multi-path drivers are able to find the working
path in case of any of these failures happens.
Configuring disks for DB2 data
You should always use dedicated LUNs for DB2 data and transaction logs to
achieve optimum performance as suggested in DB2 best practices. This means
that you should not use the LUNs or the file systems under the LUNs for any
other purpose. Otherwise, you might end up generating competition on I/O
resources.
You can choose from two different techniques on how you are going to use the
dedicated LUNs:
 Raw device mapping (RDM)
 VMFS
VMware has a feature called raw device mapping that allows you to access the
LUNs as they were locally attached to the virtual machine. Normally, you present
a LUN to the host machine and use it as your datastores.
Each VMware datastore has a file system called VMFS. On the top of this file
system you are able to create virtual disks, which you can use to store your
virtual machine data. Virtual machines see these virtual disks as physical disks.
There are certain differences in how RDM and VMFS flat files will perform as
your virtual disks. RDM does not have the overhead of an additional file system,
but lacks the flexibility of VMFS datastores. Tests imply that there is no noticeable
difference in performance when using RDM instead of VMFS datastores. VMFS
can even be faster than RDM on certain workloads. Thus, we recommend always
using VMFS instead of RDM virtual disks unless there are other reasons to use
it.
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Figure 4-6 shows one possible way of setting up datastores for DB2 storage
paths.
Figure 4-6 Datastores for DB2 storage paths (Copyright © 2009 VMware, Inc. All rights
reserved.)
Here we have four datastores:




ESXSTOR_1
ESXSTOR_2
ESXSTOR_3
ESXSTOR_4
We could use these as our DB2 storage paths. We could now create one virtual
disk for each of these storage paths, and use this virtual disk as a DB2 storage
path. When the storage paths are dedicated for DB2 storage paths, we are able
to achieve optimal I/O performance. In 4.3, “Virtual machine setup” on page 92,
we show how we use VMware datastores to set up virtual disks and create
storage paths on them.
Setting the path switching policy
With the path switching policy, you define how you access the datastores with the
failover capable equipment. The path switching policy is not only used to recover
from the hardware failures, but also to provide load balancing when required.
Once you have added your datastores you must choose which path switching
policy you are going to use for your datastores. You should have multiple paths
available to access the LUNs, as explained in “Failover configuration” on
page 88. These paths can be used not only for failover, but also for load
balancing. The patch switching policy that you choose not only effects on how
your systems behave on failover, but also how much the load is balanced over
the multiple paths.
There are three different options that you can choose from:
 Fixed: This policy uses a fixed active path to access the LUN. You are able to
define which HBA is the preferred path for the target LUN.
 Most Recently Used (MRU): With this option you are able to access the LUN
through the most recently used HBA.
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DB2 Virtualization
 Round Robin (RR): With this option you get load balancing across the HBAs.
The I/O requests are balanced over the HBAs.
Even though you choose fixed as your path switching policy, you can still have
load balancing over your datastores. When setting fixed for the path switching
policy you are able to set the preferred path. The preferred path will always be
used to access the LUN when the LUN is accessible through the preferred path.
In our test environment we have two Fibre Channel HBAs. We can set up our
datastores so that datastore1 and datastore3 are accessible through HBA1, and
datastore2 and datastore4 are accessible through HBA2. With this setup, the
load is balanced between two Fibre Channel HBAs.
If we choose MRU as the path switching policy, we will not have as much control
over the load balancing since we cannot guarantee that the path will stay fixed. In
case of failover, no matter what path switching policy you use, the LUN will be
accessed through the working paths.
In case of failover, in all three path switching policies the path to the LUN will
always be changed so that the LUN is usable. Even if you use the fixed policy
and have defined a preferred HBA, the preferred HBA is not used if the LUN is
not accessible through it. When the path through the preferred HBA is available
again, the preferred HBA will be used if you use the fixed path switching policy. If
you are with the MRU, the path will remain where it was set after the failover.
To obtain the best load balancing, we recommend that the RR path switching
policy goes with the dedicated datastores. If you are not using the dedicated
datastores, you might want to consider using balanced fixed paths.
You are able to change the path switching policy for your hosts through the
vSphere Client using the following steps:
1. Choose the host that you want to modify.
2. Choose the Configuration tab.
3. From Hardware panel at the left, choose Storage.
4. Right-click the datastore that you want to modify and choose Properties.
5. Choose Manage Paths and define the path switching policy for your
datastore.
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4.3 Virtual machine setup
In this section we discuss how to set up and deploy virtual machines. We
concentrate on setting up a virtual machine for DB2. We have emphasized the
importance of I/O throughout this book, and this section is no exception. We
concentrate on how to set up optimized storage for DB2. We focus on the
following topics:
 Setting up the virtual machine
 Setting up CPU, memory, and storage
 Configuring the virtual machine resource settings
4.3.1 Creating virtual machine
To get started you must create a virtual machine. This can be done through
vSphere Client:
1. Choose Inventory: Hosts and clusters.
2. Right-click either Datacenter, Cluster, resource pool, host cluster, or individual
host machine and choose New Virtual Machine.
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DB2 Virtualization
3. This launches the New Virtual Machine Wizard. The wizard guides you
through the initial virtual machine setup steps. Figure 4-7 shows the summary
page of the wizard.
Figure 4-7 Create New Virtual Machine wizard (Copyright © 2009 VMware, Inc. All rights
reserved.)
Among the few items that you must set up, the most important ones for DB2
performance are CPU, memory, and I/O.
CPU
The processor load between virtual processors will be shared between logical
processors on the host machine. If the host machine is hyper threading (HT)
capable and the HT is enabled, each processor core equals to two logical
processors, so the total number of the logical processors would be two times the
number of processor cores. If the host machine does not have HT enabled, the
number of logical processors equals the number of physical processor cores.
As shown in Figure 4-7, we set up our DB2 virtual machine to have eight virtual
processors, which is the maximum that ESX/ESXi supports. By defining the
maximum of eight virtual processors, we ensure that the processor load will be
divided between the maximum number of logical cores. Note that if your host
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machine has eight or fewer logical processors, you should think carefully about
how many virtual processors you will assign to the virtual machine. It would not
be the best practise to assign as many virtual processors to the virtual machine
as the system has logical processors.
Memory
We start with 2 GB of memory. The amount of memory can be adjusted easily
later just as the number of virtual processors can.
For the database server we want to have a dedicated memory. VMware is
capable of creating and using swap file for virtual machines. This swap file is
used when VMware does not have enough physical memory resources to be
allocated for virtual machines. The size of the swap file is the difference of the
values between the actual virtual machine memory size and reservation. To
ensure that we have all the memory dedicated and not to use a swap file, we set
the reservation value to be the same as the amount of virtual machine memory.
When editing the virtual machine settings with vSphere Client, we choose the
Resources tab, select Memory, and set reservation to 2048 MB, as shown in
Figure 4-8.
Figure 4-8 Using dedicated memory (Copyright © 2009 VMware, Inc. All rights reserved.)
Be aware that although the amount of memory and the number of virtual
processors can be changed dynamically with a proper VMware license, you
might not be able to make changes without rebooting if the guest OS does not
support hot-plug memory or CPU. If this is the case, you must first shut down the
virtual machine, then adjust the values and boot the virtual machine with the
adjusted memory or CPU values.
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DB2 Virtualization
I/O and disk setup
We first place both the virtual machine configuration files and the operating
system virtual disk under datastore storage1. Next we create the storage paths
for DB2. Since our test environment only has four storage paths, we are not able
to use dedicated datastores for DB2 data and transaction logs.
We checked the Edit virtual machine settings before completion option on
the New Virtual Machine Wizard. When we click Continue, we are able to add
more hardware. We choose Add ∅ Hard Disk ∅ Next ∅ Create a new virtual
disk to reach the panel where we are able to specify a datastore on which we
want to store our virtual disk, as shown in Figure 4-9.
Figure 4-9 Creating virtual disk for DB2 storage path (Copyright © 2009 VMware, Inc. All
rights reserved.)
Note that we do not check Thin Provisioning, which allocates the disk space in
an on demand basis. We use Thick Provisioning to have the disk space
specified allocated immediately.
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We click Next and get the panel that lets us choose which virtual device node to
use. The default is next available. Since the operating system disk is under
SCSI(0:0), the next default is SCSI(0:1). We do not choose that. Instead, we
choose SCSI(1:0) as our virtual device node for our first storage path because
we want our data disks to be available through a different virtual SCSI adapter
from our operating systems. See Figure 4-10.
Figure 4-10 Virtual device node (Copyright © 2009 VMware, Inc. All rights reserved.)
After we click Next ∅ Finish our first disk is ready. Since we are going to have a
total of four storage paths for our DB2 data, we continue by adding three virtual
disks more after we have complemented creating the first one. The remaining
three ones are similar to the first one, but are placed in different datastores:
datastore2, datastore3, and datastore4 with the virtual device nodes SCSI(1:1),
SCSI(1:2), and SCSI(1:3), respectively. We still need two additional virtual disks
for DB2 transaction logs and test data. We assign virtual device nodes SCSI(0:1)
and SCSI(0:2) for the last two virtual disks.
Depending on the guest OS support for hot-plug disks and the type of VMware
license, you are able to add, remove, or even resize disks dynamically without
powering off the virtual machine.
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DB2 Virtualization
4.3.2 Setting up operating system environment
Now that we have set up the physical aspect of our virtual machine, we can
continue installing the operating system (OS) on it. In our test environment we
use SuSE Linux Enterprise 10 64-bit edition and Microsoft Windows 2008 Server
as our test virtual machines. The OS installation is done the standard way.
Before setting up the OS environment, you should install VMware Tools. With the
VMware Tools, you can benefit from a significantly better display and the network
adapter drivers that are designed especially for VMware virtual machines. To be
able to utilize all the capabilities of clones and templates VMware Tools are
required as well. Refer to VMware documentation for how to perform the VMware
tools installation for your guest OS.
In our example, the virtual disks for DB2 data were added when the virtual
machine was created. We did not create any file system on these disks during
the OS installation. It is possible to add virtual disks online to the virtual machine.
Depending on the operating systems, the disks are usually handled as the
hot-pluggable disks, and the OS is able to initialize them without the need for
rebooting the OS. In our tests both SuSE Linux Enterprise 10 and Microsoft
Windows 2008 Server were able to detect virtual disks that were added to the
system online. Also, both of the operating systems are able to detect and utilize
changes on the virtual disk sizes online without reboot.
Setting up the file systems for DB2 on Linux
We create four virtual disks to be used for DB2 database storage paths. We add
one additional file system for transaction logs. Our virtual disk for the OS is first
seen as the attached SCSI disk on our system. It is seen as /dev/sda by the OS.
For the OS some prefer to use Logical Volume Management (LVM). With LVM
you are able to benefit from all the features and flexibility that it offers. You also
can use LVM for the DB2 database storage paths. However, for the maximum
performance we recommend not utilizing LVM, since it adds overhead to the
system.
To set up the file systems for DB2 data, we must find the device names for the
disks first. This can be done, for example, by checking with the dmesg command
what disk has been attached to the system, as shown in Example 4-1.
Example 4-1 Finding attached disks
# dmesg | grep "Attached scsi disk "
sd 0:0:0:0: Attached scsi disk sda
sd 0:0:1:0: Attached scsi disk sdb
sd 0:0:2:0: Attached scsi disk sdc
sd 1:0:1:0: Attached scsi disk sdd
sd 1:0:2:0: Attached scsi disk sde
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sd 1:0:3:0: Attached scsi disk sdf
sd 1:0:4:0: Attached scsi disk sdg
We set up our test environment so that we have file systems for DB2 data under
the virtual device node SCSI(1:x), as shown in Figure 4-10 on page 96. We
created two additional virtual disks for transaction logs and test data under the
storage1 datastore. We set their virtual device node to SCSI(0:1) and SCSI(0:1).
These two disks are seen as /dev/sdb and /dev/sdc by the OS. The devices
/dev/sdd, /dev/sde, /dev/sdf, and /dev/sdg are the disks on which we place our
DB2 data. Note that since we have set up our transaction logs under the same
LUN where we are storing the OS and our first DB2 storage path, this is not an
optimal solution considering performance. On a high-load production system you
should place transaction logs and DB2 storage paths under dedicated LUNs.
Now that we have identified our disks, we create one primary partition for each of
them. We used the fdisk command to create the partition. We then created an
ext3 journal file system for each disk by using the mkfs -t ext3 /dev/sdx1
command, where x refers to the corresponding disk device. Next we labeled all
the file systems with the tune2fs command. For instance, /dev/sdd1 was labeled
as data1 with command tune2fs data1 /dev/sdd1. Next we added the lines
shown in Example 4-2 to /etc/fstab for DB2 data and transaction logs.
Example 4-2 Example of /etc/fstab
LABEL=data1
LABEL=data2
LABEL=data3
LABEL=data4
LABEL=db2logs
/db2data/data1
/db2data/data2
/db2data/data3
/db2data/data4
/db2logs
ext3
ext3
ext3
ext3
ext3
defaults
defaults
defaults
defaults
defaults
1
1
1
1
1
2
2
2
2
2
By labeling the partitions, you can ensure that when you add new virtual disks,
the file systems will be mounted properly even if the device names for the virtual
disks are changed. Now we are able to mount all our file systems for DB2 data
and transaction logs. Before creating the database under them, we must change
the file system owner and corresponding group to the DB2 instance owner.
Example 4-3 shows the file system layout for DB2.
Example 4-3 Linux file system layout for DB2
Filesystem
/dev/sdd1
/dev/sde1
/dev/sdf1
/dev/sdg1
/dev/sdb1
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DB2 Virtualization
Size
10G
10G
10G
10G
10G
Used
0G
0G
0G
0G
0G
Avail Use% Mounted on
10G 100% /db2data/data1
10G 100% /db2data/data2
10G 100% /db2data/data3
10G 100% /db2data/data4
10G 100% /db2logs
When you add or change the size of the virtual disks on Linux, you can use the
rescan-scsi-bus.sh utility to detect the changes dynamically.
Setting up the file systems for DB2 on Windows
As on modern Linux distributions, you are able to add and change the size of the
existing virtual disks dynamically on the Windows 2008 Server. You can add and
initialize your virtual disks by using the Disk Management tool. We initialized the
disks as dynamic disks and used NTFS. We labeled the disks to reflect the usage
for DB2, as illustrated in Figure 4-11.
Figure 4-11 Windows file system layout
On Windows 2008 Server, to detect dynamic changes for virtual disks, use the
Server Manager utility and right-click Disk Management under Storage and
choose Rescan Disks.
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4.3.3 Resource settings
On vSphere you are able to prioritize CPU, memory, and I/O usage between your
virtual machines. You can define three different values for how the resources are
allocated:
 Shares: By default all the virtual machines are set to have an equal amount of
shares concerning CPU, memory, and I/O resources. This means that the
virtual machines are provided with an equal amount of resources when there
is contention among them.
 Reservation: You can set the minimum amount of processor resources in
MHz and the minimum amount of memory in megabytes that a virtual
machine will be granted when it is powered on. By default the reservation is
set to 0.
 Limit: You can define the upper bound of processor and memory resources
for a virtual machine. For the processor you define the maximum number of
CPU resources in MHz and for memory the maximum amount of RAM in
megabytes that a virtual machine is able to get on any condition. By default
the limit is set to unlimited.
You are able to change the resource setting for CPU and memory dynamically
when the virtual machines are online. If you want to change the shares for disk
I/O, you must first power off the virtual machine.
To change the default resource settings with vSphere Client, right-click the
corresponding virtual machine and select Edit Settings, then select the
Resources tab. This opens the resources panel, as shown Figure 4-12.
Figure 4-12 Resource settings (Copyright © 2009 VMware, Inc. All rights reserved.)
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DB2 Virtualization
As you can see from Figure 4-12 on page 100, besides CPU, memory, and disk,
there is also a selection for Advanced CPU. With this selection, you are able to
set the hyperthreaded core sharing and the scheduling affinity. By default the
hyperthreaded core sharing is set to Any. This means that the virtual processors
are able to share the cores with any virtual processor on other virtual machines
or on the same virtual machine.
With the scheduling affinity, you are able to allocate specific logical processors to
be scheduled exclusively to this guest. Refer to the VMware documentation for
how to change these settings from their defaults.
Resource pools
You can create resource pools to have more control over how resources are
shared between guests. For instance, you could create individual resource pools
for the test servers and production servers. You might want to provide more
resources for the production servers to be able to handle production workloads,
which usually has higher priority.
Since vSphere 4 resource pools can be defined hierarchically. The child resource
pool inherits the resources from its parent pool.
Use resource settings and resource pools to prioritize and tune the resource
allocation for your database servers accordingly. For more information about
resource management refer to vSphere Resource Management Guide, available
at following site:
http://www.vmware.com/pdf/vsphere4/r40/vsp_40_resource_mgmt.pdf
4.3.4 Monitoring the resource usage
VMware vSphere offers well-developed and easy-to-use monitoring tools. You
are able to monitor the resource usage for processor, memory, and I/O with
vSphere Client. You can monitor the resources on both the host and the guest
level. This information about resources and how they are used provides you with
valuable data about how your virtual machines behave in a virtualized
environment. You can use this information to tune your database server and
manage your resource settings for a particular virtual machine, as well as the
entire virtualized environment.
For instance, by monitoring the resource usage for your database server, you
might be able to find the bottlenecks on the server very easily. By changing the
resource settings for the virtual server, you might be able to fix the problem online
just by adding the lacking resource.
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4.3.5 Cloning and templates
With VMware vSphere you can clone the existing virtual machines. Alternatively,
you can use an existing virtual machine to create a template, which you can use
later to deploy new virtual machines with pre-installed software and standardized
hardware components. When you create a clone or convert a template to a
virtual machine, you are able to change, for instance, network settings before the
cloned or converted virtual machine is booted. Use of the VMware cloning
feature and templates simplifies system administrator work and saves a
significant amount of time.
Utilizing VMware cloning capabilities and templates with DB2 you are able to, for
instance, build a test environment from a production environment. Or you can
build a DB2 server template with DB2 pre-installed and configured.
If you are cloning your production database, you probably want to change the
name of the database and possibly even rename the instance. With DB2, both
renaming the database and instance are easily done with the db2relocatedb
utility. You must create a basic configuration file where you define the database
and instance names.
Example 4-4 shows a simple configuration file to be used with db2relocatedb.
With this configuration file you change only the database name and keep both
the database path and the instance name as they were.
Example 4-4 db2reloactedb configuration file
DB_NAME=PRODDB,TESTDB
DB_PATH=/db2data/data1,/db2data/data1
INSTANCE=db2inst1,db2inst1
The db2relocatedb utility has the following syntax:
db2relocatedb -f <config_file>
When you clone or convert a template to a virtual machine, you must edit
db2nodes.cfg according the changes in the host name and IP address.
4.4 DB2 setup and configuration
In this section we describe the installation and the setup of a DB2 environment
on a VMware virtual machine. We focus on the best practices to achieve optimal
performance for a DB2 database.
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DB2 Virtualization
4.4.1 Installation
The DB2 installation in a VMware virtual machine depends on the chosen
operating system for the virtual machine, just like installing DB2 on a physical
server. There is nothing specific to have in mind for VMware. You can just follow
the instructions from the DB2 installation guides at the Information Center:
http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.db2.luw.qb.
server.doc/doc/c0024080.html
4.4.2 Setup
In a virtualized environment, you can particularly benefit from the DB2 autonomic
features and the compression technologies introduced in 2.1.2, “Features and
functions” on page 15. The database engine is capable of detecting changes in
the number of processors and the memory size dynamically online without the
need to restart the instance. DB2 will apply the necessary adjustments
automatically for the database heaps and other parameters to optimize
performance.
Storage
When setting up the storage systems for DB2 there are several topics to keep in
mind. The most important ones are:
 Place the transaction log files and the data log files on separate file systems
or on separate disks. In Example 4-5 we show how to set up different paths
for the datastore during the database creation.
Example 4-5 Database creation with storage paths
CREATE DATABASE virtdb AUTOMATIC STORAGE YES ON /db2data/data1,
/db2data/data2, /db2data/data3, /db2data/data4 DBPATH ON /db2logs
 Note that in Example 4-5 we use automatic storage as well. This feature
provides a great relief for DBAs by automating the management of the table
space containers. DB2 creates the table space containers automatically on
the given data paths. This feature also helps with performance, as DB2
places the table space containers in a way that allows the most concurrent
access. If you are running out of storage you just must add additional data
paths and DB2 will take care of the optimal distribution of the data. We show
the simple command for this action in Example 4-6.
Example 4-6 Adding storage path
ALTER DB virtdb ADD STORAGE PATH /db2data/data5, /db2data/data6
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 You should set the EXTENTSIZE parameter of the CREATE TABLESPACE
command to at least the number of pages that are included in an entire RAID
stripe. A multiple of this RAID stripe size is fine as well. Figure 4-13 shows an
example.
Figure 4-13 Extentsize: RAID stripe size
 Use the NO FILE SYSTEM CACHING parameter of the CREATE
TABLESPACE command for all data and index table spaces. Because this
data is already cached in the buffer pools, there is no need for additional
caching at the file system level.
 Use the FILE SYSTEM CACHING parameter of the CREATE TABLESPACE
command for LOB table spaces. This data is not cached in the buffer pools,
so enabling caching on the file system level increases performance.
Memory
For optimal memory usage the Self Tuning Memory Manager (STMM) should be
switched on (SELF_TUNING_MEM=ON, default in DB2 9.7). STMM tunes
several memory heaps according to the workload on your database when they
are set to AUTOMATIC. Table 4-1 lists these memory heap parameters.
Table 4-1 Memory heap parameters for STMM
104
Parameter name
Value
DATABASE_MEMORY
AUTOMATIC
LOCKLIST
AUTOMATIC
MAXLOCKS
AUTOMATIC
PCKCACHESZ
AUTOMATIC
SHEAPTHRES_SHR
AUTOMATIC
SORTHEAP
AUTOMATIC
DB2 Virtualization
Parameter name
Value
DBHEAP
AUTOMATIC
STMTHEAP
AUTOMATIC
APPLHEAPSZ
AUTOMATIC
APPL_MEMORY
AUTOMATIC
STAT_HEAP_SZ
AUTOMATIC
In Table 4-2 we present the parameters that are responsible for an optimal I/O
performance between the buffer pools and the storage.
Table 4-2 Thread-based parameters for STMM
Parameter name
Value
NUM_IOCLEANERS
AUTOMATIC
NUM_IOSERVERS
AUTOMATIC
DFT_PREFETCH_SZ
AUTOMATIC
Table 4-3 provides the application-specific parameters influenced by STMM.
Table 4-3 Application specific parameters for STMM
Parameter name
Value
MAXAPPLS
AUTOMATIC
AVG_APPLS
AUTOMATIC
For a detailed description of each of these parameters go to:
http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.db2.luw.admin
.config.doc/doc/r0005181.html
Automatic maintenance
In this section we discuss self-healing features of DB2 as well as automatic
database object management.
Self-healing
To set up the self-healing features of DB2 you can either use the DB2 Health
Monitor (deprecated in DB2 9.7) or the new feature called Data Studio
Administration Console. You can enable several health indicators and define
thresholds for them. If these thresholds are violated, DB2 raises an alert. You can
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define actions (scripts) that DB2 will execute in case of a violation. These
self-healing features of DB2 can save a lot of time for the responsible DBAs.
Automatic object maintenance
The automatic object maintenance feature enables DB2 to take care of the
regular maintenance tasks BACKUP, RUNSTATS, and REORG for DBAs. DB2
senses the workload occurring on the database and on your tables. Based on
internal indicators, the DB2 engine decides whether it is necessary to run one of
the defined processes.
By defining policies for these processes you can, for example, tell DB2 what
tables should be checked for RUNSTATS needs. These policies are provided to
DB2 in XML format. You can find several XML example files in the samples
directory of your instance.
You also can define maintenance windows on the periods when the database
server has lower workloads to run the maintenance tasks. For BACKUP,
RUNSTATS, and REORG processes, you can define whether these jobs must be
executed within the maintenance window defined or whether they are allowed to
run outside the maintenance window as well.
Be aware that most virtualization product vendors also provide backup utilities for
their virtual machines. These utilities are not sufficient if you are running
databases in the virtual machines. They cannot guarantee the consistency of
your database because they just create snapshots of the database files.
Compression
Though we have several types of compression built in DB2, be careful when you
use them. If you enable compression features while the virtual machine is
already CPU-bound (> 90%), then the system will probably become slower due
to the compression/decompression overhead on the CPU. Because the created
compression dictionary occupies storage as well, even if the system is not
CPU-bound, you still must consider whether the compression (for example, row
compression) makes sense for a certain table. Small tables do not qualify for
compression then.
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DB2 Virtualization
DB2 provides the inspect command for estimating the storage savings for
enabling row compression on a table. You can run it from the DB2 command line.
We introduce this command in Example 4-7. This command creates a binary
output file in the db2dump directory of your instance. The binary file can be
translated into a text file using the db2inspf utility. The usage of this utility is also
shown in Example 4-7.
Example 4-7 inspect and db2inspf command
db2 "INSPECT ROWCOMPESTIMATE TABLE NAME RESULTS KEEP virtdb.bin"
db2inspf virtdb.bin virtdb.txt
Example 4-8 shows the output of the db2inspf utility. You can see from this
example that the storage savings are 46% of the original storage amount.
Example 4-8 db2inspf output
DATABASE: SAMPLE
VERSION : SQL09050
2009-08-11-16.03.00.361000
Action: ROWCOMPESTIMATE TABLE
Schema name: OPTIM
Table name: EMPLOYEE
Tablespace ID: 2 Object ID: 6
Result file name: virtdb.bin
Table phase start (ID Signed: 6, Unsigned: 6; Tablespace ID: 2) :
OPTIM.EMPLOYEE
Data phase start. Object: 6 Tablespace: 2
Row compression estimate results:
Percentage of pages saved from compression: 46
Percentage of bytes saved from compression: 46
Compression dictionary size: 13312 bytes.
Expansion dictionary size: 10224 bytes.
Data phase end.
Table phase end.
Processing has completed. 2009-08-11-16.03.00.407000
The inspect command works for row compression only. To get an impression of
the amount of savings for index compression or XML compression you must run
administrative table functions delivered with DB2.
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4.5 Conclusions
By setting up a test environment, running thorough tests, and following the DB2
best practices on a VMware virtualized environment, we came to the following
conclusions:
 On DB2 storage, use SAN disks and dedicated LUNs for maximum
performance. Use virtual disks placed on dedicated VMFS file systems on the
dedicated LUNs on the SAN system. RDM does not offer better performance
and lacks the flexibility of virtual disks on VMFS. Utilize DB2 automatic
storage to stripe over the file systems.
 Set the path switching policy accordingly. Setting the path switching policy to
reflect disk and SAN setup has a great effect on the I/O performance. When
you are using dedicated LUNs with active/active capable SAN equipment, set
the path switching policy to round robin.
 Properly tune the DB2 resource settings. This gives you the ability to prioritize
and handle the DB2 server workloads properly, especially when there is
competition on resources.
 Use vSphere monitoring tools to set and tune resource settings. Utilize the
rich set of monitoring capabilities that vSphere has to offer to tune your
virtualized environment. You also can use this information to tune your DB2
configuration settings.
 Use the DB2 autonomics features to fully utilize dynamic changes in a virtual
environment. To be able to detect the changes in the operating environment
and act as required, use STMM and all other autononomic DB2 features.
 Utilize vSphere templates and cloning capabilities. vSphere offers efficient
tools to create templates and clone virtual machines. DB2 can be cloned
easily and deployed by converting the template to a virtual machine.
 Install VMware Tools: To be able to obtain all the benefits of a VMware
virtualized environment, you should always install the latest VMware Tools for
your guest OS.
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5
Chapter 5.
Hyper-V
Microsoft Windows Server 2008 Hyper-V technology is a key feature that is found
on Microsoft Windows Server 2008. It brings forth many benefits of virtualization,
such as server consolidation for Windows Server 2008 users without using and
purchasing other third-party products. This chapter describes information related
to DB2 virtualization with Hyper-V including:
 High-level overview of Hyper-V architecture and requirements
 High-level overview of Hyper-V and virtual machine setup and configuration
 Configuration of DB2 in a Hyper-V virtual machine environment
© Copyright IBM Corp. 2009. All rights reserved.
109
5.1 Overview
Microsoft Hyper-V hypervisor-based virtualization technology is included in many
64-bit editions of Windows Server 2008. A beta version of Hyper-V shipped with
the generally available version of Windows Server 2008 R1 and the finalized
version became available through a Windows update (KB950050) on June 26,
2008. Furthermore, a stand-alone version of Hyper-V is available without other
Windows server components through the free Microsoft Hyper-V Server 2008
product.
5.1.1 Architecture
A hypervisor is a thin layer of software between the underlying hardware and
each virtual machine partition that contains an operating system (OS). Hyper-V
is a type 1 hypervisor, as it runs directly on the host hardware. Figure 5-1
illustrates the Hyper-V architecture.
Figure 5-1 Hyper-V architecture
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DB2 Virtualization
Each partition in the system is isolated from one another, providing an area
where the virtual machine can execute without interference from other partitions.
Regardless of the way that Hyper-V is installed in the system (see 5.2,
“Installation and setup of Hyper-V” on page 112, for different ways to get
Hyper-V), a parent partition must be present in order to hold the primary
operating system installation, as well as the virtualization stack of Hyper-V. This
virtualization stack in turn has direct access to the hardware, providing the link
between the host hardware and the child partitions on the system. The child
partitions holding other virtual machines are created through the parent partition
by the use of a hypercall application programming interface (API).
Since child partitions do not have direct access to the hardware, such as the
CPU, memory, and other devices, it views these resources through the VMBus
as virtual devices. The VMBus allows for communication to occur between the
parent and multiple child partitions. It is used by the virtualization service
provider (VSP) running on the parent partition and virtualization service client
(VSC) running on the child partition to exchange data, requests, and responses.
Hyper-V also has a specific feature in order to speed up I/O processes in child
partitions, allowing the use of the VMBus directly by virtual devices. Often
described as enlightened, these child partitions require the use of
hypervisor-aware virtual device drivers that are already part of the OS or are
installed as part of Integration services. See “Disk configuration
recommendations for virtual machines” on page 121 for more information.
5.1.2 Requirements
Microsoft Hyper-V has specific hardware requirements that must be met:
 A machine containing an x86_64-based (commonly referred to as x64)
processor.
 The availability of instructions on the CPU for hardware-assisted
virtualization, commonly found in later Intel and AMD produced CPUs with the
marketed labels of Intel VT and AMD-V, respectively.
 The ability for the CPU to support the No eXecute (NX) bit, marketed by Intel
as the eXecute Disable (XD) bit and by AMD as Enhanced Virus Protection.
In addition, hardware Data Execution Prevention (DEP) must be enabled.
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For the second and third items in the above list, they must be enabled in the
BIOS of the machine. Figure 5-2 shows an image of an IBM System x3650 BIOS,
with the appropriate required settings highlighted.
Figure 5-2 Required CPU options of IBM System x3650 BIOS for Hyper-V
It is important to note that if the BIOS changes shown in Figure 5-2 are
necessary, you must invoke a hard reboot to the system (that is, turn off and then
turn back on the system) in order to save the settings correctly.
5.2 Installation and setup of Hyper-V
To attain Hyper-V for your Windows-based machine, you must install one of the
following:




Microsoft Windows Server 2008 Standard Edition x64
Microsoft Windows Server 2008 Enterprise Edition x64
Microsoft Windows Server 2008 Datacenter Edition x64
Microsoft Hyper-V Server 2008
Hyper-V is one of many roles that is available within Windows Server 2008. For
more information about the Hyper-V role as well as the standalone Hyper-V
Server 2008, visit the Microsoft Windows Server 2008 Virtualization with Hyper-V
Web site at:
http://www.microsoft.com/windowsserver2008/en/us/hyperv-main.aspx
Also see the Hyper-V Server 2008 Web site at:
http://www.microsoft.com/hyper-v-server/
5.2.1 Adding the Hyper-V role in Windows Server 2008
The standalone Hyper-V Server 2008 is similar to a server core installation of
Windows Server 2008 Standard Edition with the Hyper-V and with other roles
disabled. The Hyper-V role is one of many found in Windows Server 2008 and
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can be used in conjunction with other roles. To install the Hyper-V role on a fully
installed Windows Server 2008 OS:
1. Click Start and then Server Manager at the top to open the Server Manager
window.
2. On the left pane of the Server Manager window, click Roles. Then on the right
pane click the Add Roles option to open the Add Roles Wizard.
3. Click Next until you see the Select Server Roles menu. Select Hyper-V under
Roles, then click Next (Figure 5-3).
Figure 5-3 Adding the Hyper-V role to Windows Server 2008 (Images are reprinted
with permission from Microsoft Corporation.)
4. You can optionally view more information about Hyper-V at this point. Click
Next to move to the next step.
5. The Create Virtual Networks menu appears. Creating a virtual network allows
your virtual machines running in Hyper-V to communicate through a network
with other computers. You can also change your virtual network settings at a
later time by using the Virtual Network Manager. Click Next and then Install
to start the install of the Hyper-V role.
6. Once the installation is finished, click Close. Then you are prompted to restart
the computer. The installation continues only after you have restarted the
computer.
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7. After the restart of the computer, the installation continues without further
input. Once complete, you can review the installation results and then click
Close to finish the install.
We recommend, as a normal best practice, that the Windows Server 2008
installation on the host machine only have the Hyper-V role installed on it, and
the machine be dedicated to only this role. The inclusion of other roles on the
physical server may affect performance of the virtualization server, slowing down
all the virtual machines and their installed applications. Additionally, having only
the Hyper-V role installed minimizes the need for service patches for the host
server OS and, thus, downtime for the virtual machines.
For more information about the installation of the Hyper-V role, refer to your
Windows Server 2008 documentation.
5.2.2 Network configuration for Hyper-V
Virtual network configuration for Hyper-V is handled by the Virtual Network
Manager. This tool can be accessed by going into the Hyper-V Manager
(Start → Administrative Tools → Hyper-V Manager) and then clicking the
Virtual Network Manager option on the Actions pane (the Hyper-V Manager
must be connected to the correct server). Figure 5-4 shows the initial menu of the
Virtual Network Manager.
Figure 5-4 The Virtual Network Manager of Hyper-V (Images are reprinted with
permission from Microsoft Corporation.)
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DB2 Virtualization
If you have previously added virtual networks, you see a few options on the
left-hand side. There is a listing of the current networks available to your machine
and an option to create a new virtual network (only the create a new virtual
network option will be available if you have not created any virtual networks
beforehand). When selected, the new virtual network option displays a list of
virtual networks that you can create, labeled external, internal, or private:
 External networks allow for communication between the virtual machines
residing on the server and the external network. Thus, the virtual machines
appear to other machines in the network just like normal physical machines in
terms of networking. A specific physical network adapter must be specified for
this option. Figure 5-5 illustrates an example of this type of networking.
Figure 5-5 Diagram showing an external network in Hyper-V
 Internal networks allow for communication between the virtual machines
residing on the server and the host computer. It does not allow for any
communication between the virtual machine and any external machines.
 Private virtual machine networks create a virtual network that can only be
used by virtual machines on the host machine. The host machine itself does
not have any network communications to any of the virtual machines.
We recommend, as a normal best practice, that if virtual networks require
external access to the network, that multiple network adapters be installed in the
machine, and that at least one network adapter is free only for remote
administration of the server (that is, not bound to an external virtual network).
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5.2.3 Disk configuration for Hyper-V
From a Hyper-V role installation perspective, we recommend that sufficient
physical disk and I/O bandwidth be present on the server to serve the different
virtual machines’ needs. These requirements combined with the knowledge of
the expected number of virtual machines and the workloads that will exist on the
machine will affect the disks, storage controllers, and RAID configurations that
you choose.
5.3 Creation and setup of virtual machines on Hyper-V
Once the Hyper-V role has been set up appropriately on the server, the next step
is to create and set up the various virtual machines on the system. This section
discusses this aspect of the process, as well as recommended settings for virtual
hardware for each virtual machine.
5.3.1 Creating a virtual machine
In order to create a virtual machine on Hyper-V, follow these steps:
1. Click Start → Administrative Tools → Hyper-V Manager to open the
Hyper-V Manager window.
2. Make sure that you are connected to the local computer in the Hyper-V
Manager window. If needed, on the Actions pane, click Connect to Server
and select Local Computer, then click OK.
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DB2 Virtualization
3. On the Actions pane, select New → Virtual Machine. This opens the New
Virtual Machine Wizard, as shown in Figure 5-6.
Figure 5-6 The New Virtual Machine Wizard of Hyper-V (Images are reprinted with
permission from Microsoft Corporation.)
4. Click Next to continue to the Specify Name and Location menu where you set
the name and location of the virtual machine. Click Next to continue.
5. In the Assign Memory menu, you can assign the amount of memory required
for the virtual machine. Set up the appropriate amount of memory for the type
of workload that you will be doing on this virtual machine. See “Allocating
memory for the virtual machine” on page 119 for more information. Click Next
to continue.
6. In the Configure Network menu, you can assign the specific network
connection that you would like to use with the virtual machine. The Virtual
Network Manager (see 5.2.2, “Network configuration for Hyper-V” on
page 114) determines the type of network connection (external, internal, or
private) that it is. Click Next to continue.
7. Next is the Connect Virtual Hard Disk menu, where you can choose to create
a new virtual hard disk, use an existing virtual hard disk, or attach a virtual
hard disk later. See “Disk configuration considerations for the virtual machine”
on page 119 for more information about the ramifications of this choice. We
recommend that virtual hard disks be configured at a later time (this is due to
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117
the fact that if a disk is created here it must be a dynamic expanding disk
type). Click Next to continue.
8. On the Installation Options menu, you can choose the method of installation
of the OS for the virtual machine. Once finished, click Next to continue.
9. Review your choices for the virtual machine on the summary page. When
finished, click Finish to end the wizard, and the system begins creating the
virtual machine.
5.3.2 Additional configuration of the virtual machine
Once the virtual machine has been created, there may be additional virtual
hardware configuration that is necessary in order to satisfy your requirements. In
order to edit these settings, enter the Hyper-V Manager and then select the VM
that you would like to manipulate. Right-click this entry and then in the pop-up
menu select Settings.
Setting the number of VCPUs in the virtual machine
In order to change the settings concerning the virtual CPUs (VCPUs) on the VM,
click Processor on the left side of the Settings window to view the options. (In
order to change the VCPU settings of a VM, the VM must be turned off.)
By default, each virtual machine that is created in Hyper-V has one VCPU
allocated. In order to process the workload that we would expect on the VM, we
recommend changing this value to an appropriate number. Each virtual machine
can be configured with one, two, or four VCPUs in Hyper-V, up to the limit of
physical CPUs on the system or the limits imposed by Hyper-V for a specific
guest OS. Thus, if your machine only has two physical CPUs, you are unable to
create a VM with four VCPUs in Hyper-V.
With respect to sizing the correct number of VCPUs needed for your workload,
existing guides and knowledge from the physical realm also apply to the virtual
one. If engaging in server consolidation, most likely existing data on the
hardware usage from the workload is already known, and therefore should be
leveraged to determine the appropriate sizing.
Resource control for the virtual machine is also set on this page. These settings
enable you to balance the resources for this VM versus others that are running
on the system. You are able to set the reserves and limits to each VM, and if
resources are in contention then the relative weight setting will be a factor in the
hypervisor’s determination of resource allocation.
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Allocating memory for the virtual machine
The memory that is allocated for the virtual machine has already been set in the
steps leading up to the creation of the VM. However, if you wish to change the
memory settings you can do so by clicking Memory on the left side of the
Settings window. (In order to change the memory settings of a VM, the VM must
be turned off.)
In general (as in physical systems also), 4–8 gigabytes (GB) of memory per
allocated processor core should suffice for most systems using DB2.
Disk configuration considerations for the virtual machine
In order to manipulate the virtual hard disks for your virtual machine, click the
appropriate virtual disk controller (either IDE or SCSI) on the left side of the
Settings window, and click the Add button. The window now displays settings
that you can now set for the hard disk for the VM. Two main types of hard disk
media are presented:
 A virtual hard disk (.vhd) file
 A physical hard disk
Virtual hard disk (.vhd) file
In order to add a virtual hard disk file, click New in the middle of the window to
bring up the New Virtual Hard Disk Wizard.
1. Click Next to bring up the Choose Disk Type menu. Here you can choose
from one of three different types of virtual hard disk:
– Dynamically Expanding
– Fixed Size
– Differencing
See “Differences between virtual hard disk types” on page 120 for a
description of these different types as well as a recommendation for different
scenarios. Click Next to continue.
2. In the Specify Name and Location menu, type in a name for the virtual hard
disk and specify a location on the machine’s disk where the virtual hard disk
will reside.
3. In the Configure Disk menu, you can choose to create a brand new virtual
hard disk or copy the contents of an existing physical disk. If brand new, you
must enter a size for the virtual hard disk. Click Next and then Finish to exit
the wizard.
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119
Differences between virtual hard disk types
In step 1 in “Virtual hard disk (.vhd) file” on page 119, you are able to choose
from three different types of virtual hard disks for the virtual machine. The
following are descriptions of each:
 A dynamically expanding virtual hard disk is one where the virtual hard disk
file increases in size based upon the insertion of data onto the virtual disk.
When data is deleted from the disk, the .vhd file will not automatically shrink,
but can be manually shrunk through a compact command in the Edit Virtual
Hard Disk Wizard.
 A fixed sized virtual hard disk is one where the virtual hard disk file will be
created initially at the set size, and this size will be maintained whether data is
inserted or deleted from the virtual hard disk. This pre-allocation in space on
the physical disk allows storage I/O operations to be faster than using
dynamic expanding virtual hard disks.
 A differencing virtual hard disk produces a child virtual hard disk to store
changes made to a parent virtual hard disk. The parent is not altered while
the child virtual hard disk grows as changes to the datastored on the virtual
hard disk are made.
Physical (pass-through) hard disks
Instead of using a virtual hard disk file that sits on the host machine’s file system,
you can map the disk for the VM directly to a physical hard disk or a LUN on a
SAN. This then bypasses any overhead that is caused by the host machine’s file
system. In order to set up a pass-through disk for your virtual machine:
1. Click Start → Administrative Tools → Computer Management. This brings
up the Computer Management window, with multiple choices on the left side.
Expand the Storage category, and then click Disk Management.
2. Look for the disk that you would like to attach to the virtual machine. It must
not have a partition or a file system on it, so that it can be used as a raw
device. Right-click the disk information on the left side to see a pop-up menu,
then click Initialize Disk. Select either an MBR or GPT partition style and
then click OK.
3. Ensure that the disk is placed in an offline state. If it is currently online due to
the initialize disk process, then right-click the disk information on the left and
choose Offline.
4. Return to the Settings window for the virtual machine configuration. Select the
appropriate IDE or SCSI controller and click Add. Select Physical hard disk
and you should be able to see the physical disk that you want to use in the
drop-down menu.
5. Click OK to finish adding the disk.
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Disk configuration recommendations for virtual machines
Due to the many different options available for the disk configuration for a
Hyper-V virtual machine, you must take into account the scenario where the
virtual machine will be used and configure the disk accordingly. The following are
some recommendations:
 The disk used for the storage of data is separated from the disk used for the
installation of the OS in the virtual machine. The primary boot virtual hard disk
must be using the virtual IDE controller for the OS to boot and runs in a slower
emulated mode until such time that the Integration services are started.
Separation of the OS and individual data disks (such as table space and log
disks) is also recommended in a physical implementation, and applies in a
virtual machine implementation as well.
 We highly recommend that Integration services be installed on the virtual
machine (a must if you are using the virtual SCSI controller). The installation
of Integration services allows for enlightened drivers to be used, allowing the
use of the VMBus directly by virtual devices (see 5.1.1, “Architecture” on
page 110, for more information) and therefore increasing I/O performance.
 In scenarios where the virtual machines are being used in a test or
development environment, we recommend using virtual hard disks that are
dynamic (whether it is using dynamically expanding or differencing virtual
hard disks). Both types allow for the most efficient use of the storage capacity
that is available. Differencing disks can be used in a scenario where a master
copy of the hard disk must be maintained, and only rolling in the changes as
needed to the primary virtual hard disk. As both of these types requires
allocation of physical disk space as you work on the VM, it is slightly slower
than fixed sized virtual hard disks or pass-through disks.
 In scenarios where the virtual machines are being used in a production
environment, we highly recommend using fixed sized virtual hard disks or
pass-through physical disks for the highest I/O performance. Fixed sized
disks do not require you to allocate space on the disk every time that you
insert more data onto the drive, and the pass-through disks allow for the
minimum overhead of the virtualization layer on the disk I/O. However, due to
their fixed size, these disk types will take up space on the physical disks that
may be wasted, and pass-through disks will decrease the mobility of the
virtual machine should you employ quick migration in your infrastructure. (The
use of pass-through disks requires that both Hyper-V host machines have
access to the LUN.)
 Finally, the locations of any virtual hard disk files should be contained in
separated physical disks so as to not have the disks compete for I/O
bandwidth. For example, if two virtual disks are being accessed at the same
time and they reside on the same physical disk or LUN, each disk will only
receive a maximum of 50% of the total I/O bandwidth. It is advisable to look at
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121
your specific consolidation scenario to make sure that there is a minimum of
competition for I/O bandwidth among the physical disks.
5.4 DB2 in Hyper-V environments
Once the virtual machine has been created in the Hyper-V environment, we can
proceed with the operating system and DB2 install and configuration.
5.4.1 Supported OS platforms for DB2 on Hyper-V
Table 5-1 describes the DB2 support for Hyper-V at the time of publication of this
book.
Table 5-1 DB2 supported environments for Hyper-V
Hypervisor
Architecture
Minimum guest
OS (Windows)
Minimum guest
OS (Linux)
Minimum
DB2 level
MS Windows 2008
SP2 Hyper-V
X64 System with
Intel VT or AMD-V
MS Windows
Server 2008 SP2
Not supported
DB2 9.5 FP4
DB2 9.7 GA
Note that the Quick Migration feature of Hyper-V is not supported at the time of
publication.
For the latest information about DB2-supported environments for virtualization,
visit the following Web site:
http://www.ibm.com/developerworks/wikis/display/im/DB2+Virtualization+Support
5.4.2 Installation of operating system and DB2
Once the virtual machine hardware configuration is complete, the operating
system and DB2 can be installed inside. For more information about the
installation of Windows Server 2008, refer to your Windows Server 2008
documentation.
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For more information about the installation of DB2 on Windows, refer to the
following links in the DB2 Information Center:
 DB2 9.5
http://publib.boulder.ibm.com/infocenter/db2luw/v9r5/topic/com.ibm.db2.luw.
qb.server.doc/doc/t0052773.html
 DB2 9.7
http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.db2.luw.
qb.server.doc/doc/t0052773.html
5.4.3 Configuration of DB2 in Hyper-V environments
Once the virtual machine has been set up correctly based on the aforementioned
best practices from both physical and virtual environments, the configuration of
the database in a virtual machine is not unlike one that is set up in a physical
installation.
Use of autonomics with DB2
Various autonomic features have been introduced throughout the different
versions of DB2. These autonomic technologies can result in ease of use as well
as performance enhancements, as DB2 can adjust to the virtual computing
resources that it is given.
Self Tuning Memory Manager
Self Tuning Memory Manager (STMM) was introduced in DB2 9 and simplifies
the task of memory management and configuration for the database by
automatically configuring memory settings based upon available resources and
workload needs. By default STMM is turned on with many different memory
consumers within newly created databases since DB2 9.1. Because of this, the
system will automatically adjust the memory configuration based on need,
thereby increasing performance by using the memory resources at hand in the
most efficient way. For more information about STMM, refer to the DB2
Information Center’s topic on self-tuning memory:
http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.db2.luw.admin
.perf.doc/doc/c0024366.html
Configuration advisor
When creating new databases, the configuration advisor can be used to obtain
recommendations for the initial values of certain configuration parameters for the
database such as buffer pool sizes. These recommendations are based upon
input that is given by the user as well as system information that is automatically
detected. By default, the configuration advisor is used on any new databases
created with the CREATE DATABASE command. For more information about the
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123
configuration advisor in DB2, refer to the DB2 Information Center’s topic on the
configuration advisor:
http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.db2.luw.admin
.dbobj.doc/doc/c0052481.html
Automatic maintenance
In order to ease administration and maintain peak performance without manual
intervention, automatic maintenance is available for DB2 databases. Specifically,
automatically run reorganizations of tables or indexes and automatic statistics
collection are important to maintain performance of the database, reducing
fragmentation of the storage disks and providing correct profiling data for the
DB2 optimizer, respectively. These maintenance activities can be set into either
online or offline maintenance windows, a time period that the user can define for
running these automated tasks. For more information about automatic
maintenance, refer to the DB2 Information Center’s topic on automatic
maintenance:
http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.db2.luw.admin
.dbobj.doc/doc/c0021757.html
5.5 Conclusion
Microsoft Windows Server 2008 Hyper-V technology brings forth virtualization
benefits without the need for the purchase of other third-party software. Both
DB2 9.5 and 9.7 are supported on Hyper-V and can be successfully deployed in
such an environment given the aforementioned best practices.
Here we summarize the best practices for running DB2 with Hyper-V:
 Dedicate the machine to only the Hyper-V role if possible to reduce the needs
of resources and software updates and maintenance.
 Use multiple network adapters to decrease network resource contention, and
dedicate one network adapter for remote administration of the server and
virtual machines.
 Use dynamic virtual hard disks when in test and development environments
to increase efficient use of storage, while using fixed sized virtual hard disks
when in production environments to increase I/O performance.
 Once the OS is set up correctly, make sure to install the Integration services
for Hyper-V in the virtual machine for better performance.
 Ensure that DB2 autonomic technologies are turned on in the virtual machine,
as this provides many benefits, including performance and ease-of-use
enhancements.
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A
Appendix A.
Extension of virtualization
technologies
Virtualization is becoming more popular due to its increasing ease of efficiently
utilizing and managing resources. With virtualization additional uses have
emerged as an extension of this technology. The most notable are:
 Virtual appliances (VAs)
 Cloud computing
In this appendix we provide a general overview of virtual appliances and cloud
computing. Along with this overview, a brief discussion is included about how
DB2 can take advantage of these two new emerging virtualization technologies.
© Copyright IBM Corp. 2009. All rights reserved.
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Virtual appliances
The word appliance is defined as an instrument or device designed to perform a
specific task. When people first hear the word appliance, they commonly think of
a household appliance such as a refrigerator or a stove. These two devices have
been specifically designed and built to handle food. For example, the refrigerator
is used to keep food cold, which is mainly to keep the food from spoiling before
consumption.
The word appliance is now being used in the computing world. The first reference
to the word appliance was used to identify a computer server that was dedicated
to perform a specific task. These appliances are built using dedicated hardware
components. These components were either specifically built for the server or
configured from existing components to use in the server. This type of appliance
is loosely referred to as a hardware or computer appliance.
The term hardware appliance is now more broadly used to refer a complete
solution that includes the defined hardware stack and the software stack. Early
on when the hardware appliance used a nonstandard hardware stack, the
operating system and applications had to be customized to be used on the
server. Now software stacks are created to be used on industry-standard
hardware. This type of software stack is referred to as a software appliance. The
software appliance typically includes the setup and configuration operations as
part of the appliance. Evolving from the software appliance with the use of virtual
machines are virtual appliances.
A virtual appliance, in the general sense, is a preconfigured virtual machine
image that has integrated the application software, operating system, and virtual
resources. Essentially, a virtual appliance can be broken down into two parts:
 A software appliance
 A virtual machine
A virtual machine, which is created from virtual resources, still requires the
operating system and application software to be installed before it can be fully
utilized. At a minimum, the operating system must be installed and configured
before the virtual machine can be functional. This usually involves manually
installing, configuring, and testing both the operating system and the application
software in the virtual machine environment. The same method is used for a
dedicated or stand-alone server, which in comparison would be considered a
non-virtual machine. With the introduction of software appliances, the software
stack, which could also include the operating system, is pre-packaged and
pre-configured into one image. This image is then used to deploy the software
solution to the intended server, which can be either a dedicated server or a
virtual machine.
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By extending the software appliance concept to encompass the virtual machine,
a virtual machine image can be generated. This image creation includes the
virtual machine setup along with the configuration of the operating system and
application software. The use of a virtual appliance simplifies many aspects of
offering a complete solution. The aspects that are simplified include installation,
configuration, development, deployment, and maintenance.
Installation and configuration
A virtual appliance consists of a virtual machine image that contains the
application software and operating system, along with the virtual resources for
the targeted virtual machine. This also includes the setup and configuration of
the application software, operating system, and the virtual resources.
Without using a virtual appliance the virtual machine would first have to be
manually set up and configured, which includes the virtual resources. After this
the operating system still must be manually installed and configured. Once the
virtual machine is operational the application software also must be manually
installed and configured to complete the solution. Manually installing and
configuring each component of the software stack can be time consuming and
tedious, especially when deploying more than one instance of the software
solution. Also, since the underlying physical hardware is abstracted in the virtual
machine, the operating system and the application software are configured using
the virtual resources. This lessens the time to configure the software stack since
there is no dependence on the underlying hardware or different hardware device
drivers. So a virtual appliance simplifies the setup of the virtual resources along
with installation and configuration of the operating system and application
software.
Development and deployment
As mentioned above, a virtual appliance simplifies the installation and
configuration of a software solution. This simplification helps ease the
development, packaging, and deployment of the solution. As a result, the
benefits of using virtual appliances is realized more during the deployment phase
of solution.
In the development phase, instead of spending time configuring multiple
environments for a specific instance of a solution, this time can be spent
configuring one instance of a solution that can be deployed to multiple
environments. While time is spent in the development phase to set up and
configure the virtual resources and then to install and configure the software
stack, this is the only time that these tasks are performed. Once the solution is
completed the virtual machine image can be packaged, which can then be
Appendix A. Extension of virtualization technologies
127
deployed to multiple environments that can use the virtual machine image. The
deployment of the virtual appliance only requires that the virtual machine image
be applied to the environment, with no additional need to set up or configure the
environment.
To further assist in the packaging and the deployment of virtual appliances a
standard has been established. The Distributed Management Task Force
(DMTF) has published an Open Standard: Open Virtualization Format (OVF).
Top contributing companies in the field of virtualization technologies, including
IBM, created the Open Standard in a joint effort. The DMTF describes the
specification as “an open, secure, portable, efficient, and extensible format for
the packaging and distribution of software to be run in virtual machines.” For
more information about the OVF Specification the complete document can be
downloaded from the DMTF Web site:
http://www.dmtf.org/standards/published_documents/DSP0243_1.0.0.pdf
Maintenance
When using virtual appliances the software stack is treated as a single unit, as
opposed to the individual software components. Since the software stack has
been deployed as a single unit within the virtual appliance, updates and patches
can be applied in the same manner. This eliminates the need to manually update
each individual software component in the software stack. Also, testing of the
updates and patches only must be performed once since the software stack is
not dependent on the underlying physical hardware, which can be different from
server to server where the virtual appliance is deployed. This is in contrast to
software appliances where updates and patches would need to be tested on
each hardware server where the solution is deployed.
In summary, a virtual appliance is a preconfigured virtual machine. The use of
virtual appliances helps ease the installation and configuration of the application
software and operating system with the virtual resources within the virtual
machine. This allows a software solution to be developed, packaged, and
delivered more easily than using traditional methods to deploy a solution. At the
same time the virtual appliance is less complicated to maintain and deploy.
128
DB2 Virtualization
DB2 virtual appliances
Users of DB2 in a virtualized environment can greatly benefit from the use of
virtual appliances. These VAs offer prebuilt environments with the OS and DB2
installed and configured, providing many benefits including:
 Rapid deployment of a set configuration in a data center environment
 A prepared image with all configurations necessary for demonstrations and
trials every time
 A stand-alone and complete development environment on a desktop without
affecting other applications and tools on the machine
Extensions of DB2 virtual appliances
DB2 virtual appliances in their standard form are very useful for many different
scenarios. However, there will be instances where these VAs can be improved
upon for specific deployments or tasks. For example, an independent software
vendor (ISV) may wish to include their software product that works on top of DB2
in a demonstration VA. In these cases of repackaging, DB2 virtual appliances
can be extended to include such additional software, easing the work required to
build a virtual appliance, and bringing forth all the benefits of virtualization and
appliances very quickly.
Virtual appliances are available for all editions of DB2. To attain the DB2
Express-C versions of the VA, visit the following virtualization portal Web site:
http://www.ibm.com/developerworks/wikis/display/im/IBM+Virtual+Appliances
For other editions of DB2 virtual appliances, contact your local IBM
representative or e-mail askdata@ca.ibm.com.
Cloud computing
Cloud computing is a computing model that provides a hosted service over the
internet using a connected device. It is an evolving model that has been built
upon grid computing, utility computing, and software as a service (SaaS). The
service that is offered allows scalable access to computer resources. All of the
computer resources are invisible to the users of the service since the
infrastructure is managed by a provider. Also, the use of the computer resources
is charged on demand by the provider to the users of the hosted service.
Appendix A. Extension of virtualization technologies
129
The main aspect of cloud computing is the hosting of the physical infrastructure.
This infrastructure is made up of the computing resources that provide the
hosted services. Instead of managing the infrastructure locally, the infrastructure
is managed remotely, or off-site, by a third-party provider, which eliminates the
initial cost of the physical computer resources, along with the cost and time to
manage and maintain the infrastructure since it is taken over by a third-party
provider.
In a sense cloud computing is another form of virtualization, since now the
computer resources are abstracted or virtualized to the users of the service. The
hosted service is provided using any type of connected device through the
internet. In fact, the name cloud computing is derived from how the internet is
depicted as a cloud in diagrams. The more familiar services using cloud
computing are offered using a Web portal or client software. However, now
services are being offered that allow the user to create a virtual machine or
virtual appliance that can be hosted remotely using virtualization in the cloud.
The use of virtualization allows the virtual image to be created and activated. At
the same time, virtualization allows the provisioning of the computer resources
used in the infrastructure. This is all within the scope of the cloud computing
paradigm. The computer resources offered in the cloud include CPU and
memory, but can also include storage, all of which will be available on demand as
capacity needs change. As capacity needs change, the provider can facilitate
these changes using virtualization within the infrastructure to allocate or
deallocate resources dynamically. There are two types of distinct clouds:
 A public cloud
 A private cloud
The most common cloud is a public cloud, or external cloud. A public cloud is a
cloud that is offered to the public by a third-party provider, where the resources
are shared among the users of the hosted service. The use of the resources can
be charged based on the utilization. A private cloud, or an internal cloud, is very
similar to a public cloud, and is based on clouds being built within a private
network. The service provided in a private cloud are usually offered to select
users. But using a private cloud means that the infrastructure is not hosted by a
third-party provider, which goes against the traditional meaning of cloud
computing. So hybrid clouds, or virtual clouds, are used to build private clouds
using public clouds.
Cloud computing and DB2
DB2 and other IBM Software Group products can be found in various cloud
offerings such as the IBM Cloud and on Amazon Web Services (AWS) Elastic
Compute Cloud (EC2). Both of these infrastructures use virtualization as the
130
DB2 Virtualization
main component in abstracting the hardware resources away from the customer,
and the images that are contained in these clouds are based on the
fundamentals of virtual appliances.
For more information about DB2 products on AWS EC2, visit the following Web
sites:
http://aws.amazon.com/ibm/
http://aws.amazon.com/solutions/featured-partners/ibm/
http://www.ibm.com/developerworks/spaces/cloud/
For more information about IBM Cloud and other IBM technologies for cloud
computing, visit:
http://www.ibm.com/ibm/cloud/
Appendix A. Extension of virtualization technologies
131
132
DB2 Virtualization
Related publications
The publications listed in this section are considered particularly suitable for a
more detailed discussion of the topics covered in this book.
IBM Redbooks publications
For information about ordering these publications, see “How to get Redbooks
publication” on page 136. Note that some of the documents referenced here may
be available in softcopy only.
 PowerVM Virtualization on IBM System p: Introduction and Configuration
Fourth Edition, SG24-7940
Other publications
These publications are also relevant as further information sources.
IBM DB2 for Linux, UNIX, and Windows manuals
 Administrative API Reference, SC27-2435
 Administrative Routines and Views, SC27-2436
 Call Level Interface Guide and Reference, Volume 1, SC27-2437
 Call Level Interface Guide and Reference, Volume 2, SC27-2438
 Command Reference, SC27-2439
 Data Movement Utilities Guide and Reference, SC27-2440
 Data Recovery and High Availability Guide and Reference, SC27-2441
 Database Administration Concepts and Configuration Reference, SC27-2442
 Database Monitoring Guide and Reference, SC27-2458
 Database Security Guide, SC27-2443
 DB2 Text Search Guide, SC27-2459
 Developing ADO.NET and OLE DB Applications, SC27-2444
 Developing Embedded SQL Applications, SC27-2445
 Developing Java Applications, SC27-2446
© Copyright IBM Corp. 2009. All rights reserved.
133
 Developing Perl, PHP, Python, and Ruby on Rails Applications, SC27-2447
 Developing User-defined Routines (SQL and External), SC27-2448
 Getting Started with Database Application Development, GI11-9410
 Getting Started with DB2 Installation and Administration on Linux and
Windows, GI11-9411
 Globalization Guide, SC27-2449
 Installing DB2 Servers, GC27-2455
 Installing IBM Data Server Clients, GC27-2454
 Message Reference Volume 1, SC27-2450
 Message Reference Volume 2, SC27-2451
 Net Search Extender Administration and User's Guide, SC27-2469
 SQL Procedural Languages: Application Enablement and Support,
SC23-9838
 Partitioning and Clustering Guide, SC27-2453
 pureXML Guide, SC27-2465
 Query Patroller Administration and User's Guide, SC27-2467
 Spatial Extender and Geodetic Data Management Feature User's Guide and
Reference, SC27-2468
 SQL Procedural Language Guide, SC27-2470
 SQL Reference, Volume 1, SC27-2456
 SQL Reference, Volume 2, SC27-2457
 Troubleshooting and Tuning Database Performance, SC27-2461
 Upgrading to DB2 Version 9.7, SC27-2452
 Visual Explain Tutorial, SC27-2462
 What's New for DB2 Version 9.7, SC27-2463
 Workload Manager Guide and Reference, SC27-2464
 XQuery Reference, SC27-2466
 Installing and Configuring DB2 Connect Personal Edition, SC27-2432
 Installing and Configuring DB2 Connect Servers, SC27-2433
 DB2 Connect User's Guide, SC27-2434
 Information Integration: Administration Guide for Federated Systems,
SC19-1020-02
134
DB2 Virtualization
 Information Integration: ASNCLP Program Reference for Replication and
Event Publishing, SC19-1018-04
 Information Integration: Configuration Guide for Federated Data Sources,
SC19-1034-02
 Information Integration: SQL Replication Guide and Reference,
SC19-1030-02
 Information Integration: Introduction to Replication and Event Publishing,
SC19-1028-02
Online resources
These Web sites are also relevant as further information sources:
DB2
 DB2 Information Center
http://publib.boulder.ibm.com/infocenter/db2luw/v9r5/
 Database and Information Management home page
http://www.ibm.com/software/data/
 DB2 Technical Support
http://www.ibm.com/software/data/db2/support/db2_9/
 DB2 Product Family Library
http://www.ibm.com/software/data/db2/library/
 DB2 developerWorks
http://www.ibm.com/developerworks/db2/
 DB2 for Linux
http://www.ibm.com/software/data/db2/linux/
http://www.ibm.com/software/data/db2/linux/validate/
 DB2 Universal Database V9 Application Development
http://www.ibm.com/software/data/db2/ad/
 Planet DB2
http://www.planetdb2.com/
IBM Power Systems
http://www-03.ibm.com/systems/power/
Related publications
135
Other
 VMware
http://www.vmware.com/
 Microsoft Hyper-V
http://www.microsoft.com/virtualization/
How to get Redbooks publication
You can search for, view, or download Redbooks publications, Redpapers
publications, Technotes, draft publications and Additional materials, as well as
order hardcopy Redbooks publications, at this Web site:
ibm.com/redbooks
Help from IBM
IBM Support and downloads
ibm.com/support
IBM Global Services
ibm.com/services
136
DB2 Virtualization
Index
A
active mode 88
administration notification log 18
alert 18
algorithm 21
application programming interface 111
application software 126
application workload 5
automatic object maintenance 20
automatic storage management 20
autonomics feature 16
disk drive 2
dynamic disk 99
dynamic logical partitioning 53
E
energy consumption 5
ESX 84
ESXi 83
external cloud 130
external disk 80
external network 115
B
F
bandwidth 3
bare-metal hypervisor 7
buffer pool 17, 104
failover 90–91
fdisk command 98
file system 97
full virtualization 5
C
capacity 3
capped 50
channel 3
cluster 81
communication 115
compact command 120
compression 23
computer appliance 126
computing model 129
configuration 81
Configuration Advisor 17
CPU 3
created global temporary table 28
D
database configuration 22
database parameter 17
database shared memory 21
datastore 80, 90
declared global temporary table 28
dedicated processor 51
dedicated processor partition 49
desired processing unit 50
desired virtual processor 51
© Copyright IBM Corp. 2009. All rights reserved.
G
grid computing 129
H
HADR 84
hard disk drive 2
hard drive 6
hardware appliance 126
hardware component 126
hardware management console 35, 48
hardware resource 2
hardware stack 126
hardware-assisted virtualization 5, 8
HDD 2
Health Monitor 18
high availability 82
High Availability Disaster Recovery 84
highly available 5
high-performance component 77
hosted service 129
hybrid cloud 130
hyper threading 93
hyperthreaded core sharing 101
hypervisor 4, 6, 48, 110
137
I
I/O interface 6
Index compression 26
infrastructure 5
infrastructure manageability 4
inlining 24
Integrated Virtualization Manager 48
internal cloud 130
internal network 115
isolated guest environment 37
isolated working environment 2
IVM 48
O
operating system 6, 80, 126
optimal memory configuration 21
OS-based virtualization 5
P
K
kernel-based virtual machine 39
kernel-mode 8
keyboard 44
KVM 39
L
Live Partition Mobility 35, 54
LOB 104
logical partition 48–49, 53
logical simulated environment 2
logical unit number 89
logical volume group 3
logical volume management 97
LVG 3
M
mainstream 2
management interface 77
maximum processing unit 50
maximum virtual processor 51
memory 3
memory configuration 22
memory heap 21, 104
minimum processing unit 49
minimum virtual processor 51
most recently used 90
multi-core machine 28
multi-dimensional clustering 27
multiple instance 80
N
native hypervisor 7
network adapter 115
138
network bandwidth 78
network devices 53
network infrastructure 3
network traffic 78
network virtualization 3
networking card 44
DB2 Virtualization
Paravirtualization 5
partition profile 50
passive mode 88
path switching policy 90
performance 83
permission 81
personal computer 2
physical computing environment 2
physical disk device 80
physical resource 53
physical server 3
physical storage device 3
preconfigured virtual machine image 126
private cloud 130
private virtual machine 115
privileged-mode 8
processor 29
processor core 93
processor value unit 29
public cloud 130
PVU 29
R
RAID array 87
RAM 6
raw device mapping 89
RDM 89
record identifier 26
Redbooks Web site 136
Contact us xii
resource 86
Resource management 78
resource pool 81, 101
return on investment 4, 16
role 81
root partition 38
round robin 91
row compression 25
S
SaaS 129
scalable access 129
scheduling affinity 101
SCSI adapter 96
self tuning memory manager 21
self-configuration 16–17
self-healing 16
self-managing 16
self-optimization 16
server utilization 4
server virtualization 3
service console 77
shared processor partition 49–50
socket 29
software appliance 126
software as a service 129
software stack 126
STMM 21
storage array 3, 78
storage device 53
storage i/o traffic prioritization 78
storage path 96
storage virtualization 3
sub-capacity licensing 29
V
vCenter 76
VIOS 53
virtual appliance 126
virtual clouds 130
virtual device node 96
virtual disks 80
virtual hard disk 119
virtual i/o server 35
virtual machine 2, 37, 49, 126
virtual machine image 127
virtual machine inventory 81
virtual machine monitor 4–5
virtual processor 51
virtual resource 2–3, 126
virtual SCSI controller 121
virtualization 2
vLockstep 82
VMFS 89
VMkernel 77
vSphere 76
W
workload 17, 86
T
table spaces 104
temporary table 28
test data 96
third party provider 130
total cost of ownership 4
transaction 17
transaction logs 96
tune2fs command 98
type 1 hypervisor 110
U
uncapped 50
upper boundary 51
utility computing 129
Index
139
140
DB2 Virtualization
DB2 Virtualization
(0.2”spine)
0.17”<->0.473”
90<->249 pages
Back cover
®
DB2 Virtualization
®
Learn setting up and
configuring DB2 on
PowerVM, VMware,
and Hyper-V
Leverage
virtualization
technologies
See best practices
Server virtualization technologies are becoming more
popular to help efficiently utilize resources by consolidating
servers. IBM, the first company that developed and made
available the virtual technology in1966, offers advanced,
powerful, reliable, and cost-saving virtualization technologies
in various hardware and software products including DB2 for
Linux, UNIX, and Windows. This IBM Redbooks publication
discusses and describes using IBM DB2 9 with server
virtualization.
We start with a general overview of virtualization and
describe industry server virtualization technologies available
in the market. Following the virtualization concept, we
describe in detail the setup, configuration, and management
of DB2 with three leading server virtualization technologies:
IBM System p with PowerVM, VMware, and Hyper-V.
In addition, we discuss the DB2 features and functions that
can take advantage of using server virtualization. These
features are put into practice when describing how to set up
DB2 with the three virtualization technologies discussed in
this book. This book also includes a list of best practices
from various tests performed while using these virtualization
technologies. These best practices can be used as a
guideline or a reference when setting up DB2 using these
virtualization technologies.
INTERNATIONAL
TECHNICAL
SUPPORT
ORGANIZATION
BUILDING TECHNICAL
INFORMATION BASED ON
PRACTICAL EXPERIENCE
IBM Redbooks are developed by
the IBM International Technical
Support Organization. Experts
from IBM, Customers and
Partners from around the world
create timely technical
information based on realistic
scenarios. Specific
recommendations are provided
to help you implement IT
solutions more effectively in
your environment.
For more information:
ibm.com/redbooks
SG24-7805-00
ISBN 0738433438