Novell LINUX ENTERPRISE 11 - HIGH AVAILABILITY User manual

SUSE Linux Enterprise
High Availability
Extension
www.novell.com11
February18,2010 High Availability Guide

High Availability Guide
Copyright © 2006- 2010 Novell, Inc.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU
Free Documentation License, Version 1.2 or (at your option) version 1.3; with the Invariant Section
being this copyright notice and license. A copy of the license version 1.2 is included in the section
entitled “GNU Free Documentation License”.
SUSE®, openSUSE®, the openSUSE® logo, Novell®, the Novell® logo, the N® logo, are registered
trademarks of Novell, Inc. in the United States and other countries. Linux* is a registered trademark
of Linus Torvalds. All other third party trademarks are the property of their respective owners. A
trademark symbol (® , ™, etc.) denotes a Novell trademark; an asterisk (*) denotes a third-party
trademark.
All information found in this book has been compiled with utmost attention to detail. However, this
does not guarantee complete accuracy. Neither Novell, Inc., SUSE LINUX Products GmbH, the authors,
nor the translators shall be held liable for possible errors or the consequences thereof.

Contents
About This Guide vii
Part I Installation and Setup 1
1Conceptual Overview 3
1.1 ProductFeatures.......................... 3
1.2 ProductBenets.......................... 5
1.3 Cluster Congurations . . . . . . . . . . . . . . . . . . . . . . . 8
1.4 Architecture........................... 11
1.5 What'sNew?........................... 14
2Getting Started 19
2.1 Hardware Requirements . . . . . . . . . . . . . . . . . . . . . . 19
2.2 Software Requirements . . . . . . . . . . . . . . . . . . . . . . 20
2.3 Shared Disk System Requirements . . . . . . . . . . . . . . . . . . 20
2.4 Preparations........................... 21
2.5 Overview: Installing and Setting Up a Cluster . . . . . . . . . . . . . 21
3Installation and Basic Setup with YaST 23
3.1 Installing the High Availability Extension . . . . . . . . . . . . . . . 23
3.2 Initial Cluster Setup . . . . . . . . . . . . . . . . . . . . . . . . 24
3.3 Bringing the Cluster Online . . . . . . . . . . . . . . . . . . . . . 27

Part II Conguration and Administration 29
4Conguring Cluster Resources with the GUI 31
4.1 Linux HA Management Client . . . . . . . . . . . . . . . . . . . . 32
4.2 Creating Cluster Resources . . . . . . . . . . . . . . . . . . . . . 33
4.3 Creating STONITH Resources . . . . . . . . . . . . . . . . . . . . 37
4.4 Conguring Resource Constraints . . . . . . . . . . . . . . . . . . 38
4.5 Specifying Resource Failover Nodes . . . . . . . . . . . . . . . . . 43
4.6 Specifying Resource Failback Nodes (Resource Stickiness) . . . . . . . . 45
4.7 Conguring Resource Monitoring . . . . . . . . . . . . . . . . . . 46
4.8 Starting a New Cluster Resource . . . . . . . . . . . . . . . . . . . 48
4.9 Removing a Cluster Resource . . . . . . . . . . . . . . . . . . . . 49
4.10 Conguring a Cluster Resource Group . . . . . . . . . . . . . . . . 49
4.11 Conguring a Clone Resource . . . . . . . . . . . . . . . . . . . . 54
4.12 Migrating a Cluster Resource . . . . . . . . . . . . . . . . . . . . 55
4.13 For More Information . . . . . . . . . . . . . . . . . . . . . . . 57
5Conguring Cluster Resources From Command Line 59
5.1 Command Line Tools . . . . . . . . . . . . . . . . . . . . . . . 59
5.2 Debugging Your Conguration Changes . . . . . . . . . . . . . . . 60
5.3 Creating Cluster Resources . . . . . . . . . . . . . . . . . . . . . 60
5.4 Creating a STONITH Resource . . . . . . . . . . . . . . . . . . . . 65
5.5 Conguring Resource Constraints . . . . . . . . . . . . . . . . . . 66
5.6 Specifying Resource Failover Nodes . . . . . . . . . . . . . . . . . 68
5.7 Specifying Resource Failback Nodes (Resource Stickiness) . . . . . . . . 69
5.8 Conguring Resource Monitoring . . . . . . . . . . . . . . . . . . 69
5.9 Starting a New Cluster Resource . . . . . . . . . . . . . . . . . . . 69
5.10 Removing a Cluster Resource . . . . . . . . . . . . . . . . . . . . 70
5.11 Conguring a Cluster Resource Group . . . . . . . . . . . . . . . . 70
5.12 Conguring a Clone Resource . . . . . . . . . . . . . . . . . . . . 71
5.13 Migrating a Cluster Resource . . . . . . . . . . . . . . . . . . . . 72
5.14 Testing with Shadow Conguration . . . . . . . . . . . . . . . . . 73
5.15 For More Information . . . . . . . . . . . . . . . . . . . . . . . 74
6Setting Up a Simple Testing Resource 75
6.1 Conguring a Resource with the GUI . . . . . . . . . . . . . . . . . 75
6.2 Manual Conguration of a Resource . . . . . . . . . . . . . . . . . 77
7Adding or Modifying Resource Agents 79
7.1 STONITHAgents......................... 79
7.2 Writing OCF Resource Agents . . . . . . . . . . . . . . . . . . . . 80

8Fencing and STONITH 81
8.1 ClassesofFencing......................... 81
8.2 NodeLevelFencing........................ 82
8.3 STONITH Conguration . . . . . . . . . . . . . . . . . . . . . . 84
8.4 Monitoring Fencing Devices . . . . . . . . . . . . . . . . . . . . 88
8.5 Special Fencing Devices . . . . . . . . . . . . . . . . . . . . . . 89
8.6 For More Information . . . . . . . . . . . . . . . . . . . . . . . 90
9Load Balancing with Linux Virtual Server 91
9.1 Conceptual Overview . . . . . . . . . . . . . . . . . . . . . . . 91
9.2 HighAvailability ......................... 93
9.3 For More Information . . . . . . . . . . . . . . . . . . . . . . . 94
10 Network Device Bonding 95
11 Updating Your Cluster to SUSE Linux Enterprise 11 99
11.1 Preparation and Backup . . . . . . . . . . . . . . . . . . . . . . 100
11.2 Update/Installation . . . . . . . . . . . . . . . . . . . . . . . . 101
11.3 DataConversion......................... 101
11.4 For More Information . . . . . . . . . . . . . . . . . . . . . . 103
Part III Storage and Data Replication 105
12 Oracle Cluster File System 2 107
12.1 Features and Benets . . . . . . . . . . . . . . . . . . . . . . . 107
12.2 Management Utilities and Commands . . . . . . . . . . . . . . . . 108
12.3 OCFS2Packages......................... 109
12.4 Creating an OCFS2 Volume . . . . . . . . . . . . . . . . . . . . 110
12.5 Mounting an OCFS2 Volume . . . . . . . . . . . . . . . . . . . . 113
12.6 Additional Information . . . . . . . . . . . . . . . . . . . . . . 115
13 Cluster LVM 117
13.1 Conguration of cLVM . . . . . . . . . . . . . . . . . . . . . . 117
13.2 Conguring Eligible LVM2 Devices Explicitly . . . . . . . . . . . . . 119
13.3 For More Information . . . . . . . . . . . . . . . . . . . . . . 120
14 Distributed Replicated Block Device (DRBD) 121
14.1 Installing DRBD Services . . . . . . . . . . . . . . . . . . . . . . 122

14.2 Conguring the DRBD Service . . . . . . . . . . . . . . . . . . . 122
14.3 Testing the DRBD Service . . . . . . . . . . . . . . . . . . . . . 124
14.4 Troubleshooting DRBD . . . . . . . . . . . . . . . . . . . . . . 126
14.5 Additional Information . . . . . . . . . . . . . . . . . . . . . . 128
Part IV Troubleshooting and Reference 131
15 Troubleshooting 133
15.1 Installation Problems . . . . . . . . . . . . . . . . . . . . . . . 133
15.2 “Debugging” a HA Cluster . . . . . . . . . . . . . . . . . . . . . 134
15.3 FAQs.............................. 136
15.4 Fore More Information . . . . . . . . . . . . . . . . . . . . . . 137
16 Cluster Management Tools 139
17 Cluster Resources 193
17.1 Supported Resource Agent Classes . . . . . . . . . . . . . . . . . 193
17.2 OCFReturnCodes........................ 194
17.3 Resource Options . . . . . . . . . . . . . . . . . . . . . . . . 197
17.4 Resource Operations . . . . . . . . . . . . . . . . . . . . . . . 198
17.5 Instance Attributes . . . . . . . . . . . . . . . . . . . . . . . . 199
18 HA OCF Agents 201
Part V Appendix 275
AGNU Licenses 277
A.1 GNU General Public License . . . . . . . . . . . . . . . . . . . . 277
A.2 GNU Free Documentation License . . . . . . . . . . . . . . . . . 280
Terminology 285

About This Guide
SUSE® Linux Enterprise High Availability Extension is an integrated suite of open
source clustering technologies that enables you to implement highly available physical
and virtual Linux clusters. For quick and efcient conguration and administration,
the High Availability Extension includes both a graphical user interface (GUI) and a
command line interface (CLI).
This guide is intended for administrators who need to set up, congure, and maintain
High Availability (HA) clusters. Both approaches (GUI and CLI) are covered in detail
to help the administrators choose the appropriate tool that matches their needs for per-
forming the key tasks.
The guide is divided into the following parts:
Installation and Setup
Before starting to install and congure your cluster, make yourself familiar with
cluster fundamentals and architecture, get an overview of the key features and
benets, as well as modications since the last release. Learn which hardware and
software requirements must be met and what preparations to take before executing
the next steps. Perform the installation and basic setup of your HA cluster using
YaST.
Conguration and Administration
Add, congure and manage resources, using either the GUI or the crm command
line interface. Learn how to make use of load balancing and fencing. In case you
consider writing your own resource agents or modifying existing ones, get some
background information on how to create different types of resource agents.
Storage and Data Replication
SUSE Linux Enterprise High Availability Extension ships with a cluster-aware le
system (Oracle Cluster File System, OCFS2) and volume manager (clustered
Logical Volume Manager, cLVM). For replication of your data, the High Availabil-
ity Extension also delivers DRBD (Distributed Replicated Block Device) which
you can use to mirror the data of a high availabilitly service from the active node
of a cluster to its standby node.

Troubleshooting and Reference
Managing your own cluster requires you to perform a certain amount of troubleshoot-
ing. Learn about the most common problems and how to x them. Find a compre-
hensive reference of the command line tools the High Availability Extension offers
for administering your own cluster. Also, nd a list of the most important facts and
gures about cluster resources and resource agents.
Many chapters in this manual contain links to additional documentation resources.
These include additional documentation that is available on the system as well as doc-
umentation available on the Internet.
For an overview of the documentation available for your product and the latest docu-
mentation updates, refer to http://www.novell.com/documentation.
1 Feedback
Several feedback channels are available:
• To report bugs for a product component or to submit enhancement requests, please
use https://bugzilla.novell.com/. If you are new to Bugzilla, you
might nd the Bug Writing FAQs helpful, available from the Novell Bugzilla home
page.
• We want to hear your comments and suggestions about this manual and the other
documentation included with this product. Please use the User Comments feature
at the bottom of each page of the online documentation and enter your comments
there.
2 Documentation Conventions
The following typographical conventions are used in this manual:
•/etc/passwd: directory names and lenames
•placeholder: replace placeholder with the actual value
•PATH: the environment variable PATH
viii High Availability Guide

•ls,--help: commands, options, and parameters
•user: users or groups
•Alt,Alt +F1: a key to press or a key combination; keys are shown in uppercase as
on a keyboard
•File,File >Save As: menu items, buttons
• This paragraph is only relevant for the specied architectures. The arrows mark
the beginning and the end of the text block.
This paragraph is only relevant for the specied architectures. The arrows mark
the beginning and the end of the text block.
•Dancing Penguins (Chapter Penguins, ↑Another Manual): This is a reference to a
chapter in another manual.
About This Guide ix