Novell LINUX ENTERPRISE DESKTOP 10 SP2 User manual

SUSE Linux Enterprise
Server
www.novell.com10 SP2
May08,2008 Heartbeat

Heartbeat
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Contents
About This Guide v
1Overview 1
1.1 ProductFeatures.......................... 1
1.2 ProductBenets.......................... 2
1.3 Cluster Congurations . . . . . . . . . . . . . . . . . . . . . . . 5
1.4 Heartbeat Cluster Components . . . . . . . . . . . . . . . . . . . . 8
1.5 Architecture............................ 8
2Installation and Setup 13
2.1 Hardware Requirements . . . . . . . . . . . . . . . . . . . . . . 14
2.2 Software Requirements . . . . . . . . . . . . . . . . . . . . . . 14
2.3 Shared Disk System Requirements . . . . . . . . . . . . . . . . . . 14
2.4 Preparations........................... 15
2.5 Installing Heartbeat . . . . . . . . . . . . . . . . . . . . . . . . 17
2.6 Conguring STONITH . . . . . . . . . . . . . . . . . . . . . . . 21
3Setting Up a Simple Resource 25
3.1 Conguring a Resource with the Heartbeat GUI . . . . . . . . . . . . 25
3.2 Manual Conguration of a Resource . . . . . . . . . . . . . . . . . 27
4Conguring and Managing Cluster Resources 29
4.1 Graphical HA Management Client . . . . . . . . . . . . . . . . . . 29
4.2 Creating Cluster Resources . . . . . . . . . . . . . . . . . . . . . 31
4.3 Conguring Resource Constraints . . . . . . . . . . . . . . . . . . 33
4.4 Specifying Resource Failover Nodes . . . . . . . . . . . . . . . . . 33

4.5 Specifying Resource Failback Nodes (Resource Stickiness) . . . . . . . . 34
4.6 Conguring Resource Monitoring . . . . . . . . . . . . . . . . . . 35
4.7 Starting a New Cluster Resource . . . . . . . . . . . . . . . . . . . 36
4.8 Removing a Cluster Resource . . . . . . . . . . . . . . . . . . . . 36
4.9 Conguring a Heartbeat Cluster Resource Group . . . . . . . . . . . . 37
4.10 Conguring a Heartbeat Clone Resource . . . . . . . . . . . . . . . 40
4.11 Migrating a Cluster Resource . . . . . . . . . . . . . . . . . . . . 41
5Manual Conguration of a Cluster 43
5.1 Conguration Basics . . . . . . . . . . . . . . . . . . . . . . . . 44
5.2 Conguring Resources . . . . . . . . . . . . . . . . . . . . . . . 47
5.3 Conguring Constraints . . . . . . . . . . . . . . . . . . . . . . 52
5.4 Conguring CRM Options . . . . . . . . . . . . . . . . . . . . . 55
5.5 For More Information . . . . . . . . . . . . . . . . . . . . . . . 59
6Managing a Cluster 61
7Creating Resources 103
7.1 STONITHAgents......................... 103
7.2 ResourceAgents......................... 104
7.3 Writing OCF Resource Agents . . . . . . . . . . . . . . . . . . . 104
8Troubleshooting 107
AHB OCF Agents 109
Terminology 173

About This Guide
Heartbeat is an open source clustering software for Linux. Heartbeat ensures high
availability and manageability of critical network resources including data, applications,
and services. It is a multinode clustering product that supports failover, failback, and
migration (load balancing) of individually managed cluster resources.
This guide is intended for administrators given the task of building Linux clusters. Basic
background information is provided to build up an understanding of the Heartbeat ar-
chitecture. Setup, conguration, and maintenance of a Heartbeat cluster are covered in
detail. Heartbeat offers a graphical user interface as well as many command line tools.
Both approaches are covered in detail to help the administrators choose the appropriate
tool matching their particular needs.
NOTE
This manual covers Heartbeat version 2 and higher. Whenever the authors use
the term “Heartbeat”, they refer to Heartbeat 2, even when no explicit version
number is given.
This guide contains the following:
Overview
Before starting to install and congure your cluster, learn about the features
Heartbeat offers. Familiarize yourself with the Heartbeat terminology and its basic
concepts.
Installation and Setup
Learn about hardware and software requirements that must be met before you can
consider installing and running your own cluster. Perform a basic installation and
conguration using the Heartbeat graphical user interface.
Setting Up a Simple Resource
After you have completed the basic cluster conguration, check out a quick step-
by-step instruction of how to congure an example resource. Choose from a GUI-
based approach or a command line-driven one.

Conguring and Managing Cluster Resources
Managing resources encompasses much more than just the initial conguration.
Learn how to use the Heartbeat graphical user interface to congure and manage
resources.
Manual Conguration of a Cluster
Managing resources encompasses much more than just the initial conguration.
Learn how to use the Heartbeat command line tools to congure and manage re-
sources.
Managing a Cluster
Heartbeat provides a comprehensive set of command line tools to assist you in
managing your own cluster. Get to know the most important ones for your daily
cluster management tasks.
Creating Resources
In case you consider writing your own resource agents for Heartbeat or modifying
existing ones, get some detailed background information about the different types
of resource agents and how to create them.
Troubleshooting
Managing your own cluster requires you to perform a certain amount of troubleshoot-
ing. Learn about the most common problems with Heartbeat and how to x them.
Terminology
Refer to this chapter for some basic Heartbeat terminology that helps you understand
the Heartbeat fundamentals.
1 Feedback
We want to hear your comments and suggestions about this manual and the other doc-
umentation 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.
vi Heartbeat

2 Documentation Updates
Expect updates to this documentation in the near future while it is extended to match
the capabilities of the software itself and to address more and more use cases. By using
the User Comments feature described in Section 1, “Feedback” (page vi), let us know
on which aspects of Heartbeat this guide should elaborate.
For the latest version of this documentation, see the SLES 10 SP2 documentation Web
site at http://www.novell.com/documentation/sles10.
3 Documentation Conventions
The following typographical conventions are used in this manual:
•/etc/passwd: lenames and directory names
•placeholder: replace placeholder with the actual value
•PATH: the environment variable PATH
•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
•►amd64 ipf: This paragraph is only relevant for the specied architectures. The
arrows mark the beginning and the end of the text block.◄
►ipseries s390 zseries: This paragraph is only relevant for the specied architec-
tures. 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 vii

1
Overview
Heartbeat is an open source server clustering system that ensures high availability and
manageability of critical network resources including data, applications, and services.
It is a multinode clustering product for Linux that supports failover, failback, and mi-
gration (load balancing) of individually managed cluster resources. Heartbeat is shipped
with SUSE Linux Enterprise Server 10 and provides you with the means to make virtual
machines (containing services) highly available.
This chapter introduces the main product features and benets of Heartbeat. Find sev-
eral exemplary scenarios for conguring clusters and learn about the components
making up a Heartbeat version 2 cluster. The last section provides an overview of the
Heartbeat architecture, describing the individual architecture layers and processes
within the cluster.
1.1 Product Features
Heartbeat includes several important features to help you ensure and manage the
availability of your network resources. These include:
• Support for Fibre Channel or iSCSI storage area networks
• Multi-node active cluster, containing up to 16 Linux servers. Any server in the
cluster can restart resources (applications, services, IP addresses, and le systems)
from a failed server in the cluster.
Overview 1

• A single point of administration through either a graphical Heartbeat tool or a
command line tool. Both tools let you congure and monitor your Heartbeat cluster.
•The ability to tailor a cluster to the specic applications and hardware infrastructure
that t your organization.
• Dynamic assignment and reassignment of server storage on an as-needed basis.
• Time-dependent conguration enables resources to fail back to repaired nodes at
specied times.
• Support for shared disk systems. Although shared disk systems are supported, they
are not required.
• Support for cluster le systems like OCFS 2.
• Support for cluster-aware logical volume managers like EVMS.
1.2 Product Benets
Heartbeat allows you to congure up to 16 Linux servers into a high-availability cluster,
where resources can be dynamically switched or moved to any server in the cluster.
Resources can be congured to automatically switch or be moved in the event of a re-
source server failure, or they can be moved manually to troubleshoot hardware or balance
the workload.
Heartbeat provides high availability from commodity components. Lower costs are
obtained through the consolidation of applications and operations onto a cluster.
Heartbeat also allows you to centrally manage the complete cluster and to adjust re-
sources to meet changing workload requirements (thus, manually “load balance” the
cluster).
An equally important benet is the potential reduction of unplanned service outages as
well as planned outages for software and hardware maintenance and upgrades.
Reasons that you would want to implement a Heartbeat cluster include:
• Increased availability
• Improved performance
2Heartbeat