Installation guide

12 Chapter 1:Introduction to Red Hat Cluster Manager
• Manual service relocation capability
In addition to automatic service failover, a cluster enables administrators to cleanly stop services
on one cluster system and restart them on the other system. This allows administrators to perform
planned maintenance on a cluster system, while providing application and data availability.
• Event logging facility
To ensure that problems are detected and resolved before they affect service availability, the cluster
daemons log messages by using the conventional Linux syslog subsystem. Administrators can
customize the severity level of the logged messages.
• Application Monitoring
The cluster services infrastructure can optionally monitor the state and health of an application. In
this manner, should an application-specific failure occur, the cluster will automatically restart the
application. In response to the application failure, the application will attempt to be restarted on
the member it was initially running on; failing that, it will restart on the other cluster member.
• Status Monitoring Agent
A cluster status monitoring agent is used to gather vital cluster and application state information.
This information is then accessible both locally on the cluster member as well as remotely. A
graphical user interface can then display status information from multiple clusters in a manner
which does not degrade system performance.
1.3 How To Use This Manual
This manual contains information about setting up the cluster hardware, and installing the Linux dis-
tribution and the cluster software. These tasks are described in Chapter 2, Hardware Installation and
Operating System Configuration and Chapter 3, Cluster Software Installation and Configuration.
For information about setting up and managing cluster services, see Chapter 4, Service Configuration
and Administration. For information about managing a cluster, see Chapter 8, Cluster Administration.
Appendix A, Supplementary Hardware Information contains detailed configuration information on
specific hardware devices and shared storage configurations. Appendix B, Supplementary Software
Information contains background information on the cluster software and other related information.