1.3.4. Configuration Management

The cluster configuration file, /etc/cluster/cluster.conf specifies the High Availability Add-On configuration.The configuration file is an XML file that describes the following cluster characteristics:

Cluster name — Specifies the cluster name, cluster configuration file revision level, and basic fence timing properties used when a node joins a cluster or is fenced from the cluster.
Cluster — Specifies each node of the cluster, specifying node name, node ID, number of quorum votes, and fencing method for that node.
Fence Device — Specifies fence devices in the cluster. Parameters vary according to the type of fence device. For example for a power controller used as a fence device, the cluster configuration defines the name of the power controller, its IP address, login, and password.
Managed Resources — Specifies resources required to create cluster services. Managed resources includes the definition of failover domains, resources (for example an IP address), and services. Together the managed resources define cluster services and failover behavior of the cluster services.

The cluster configuration is automatically validated according to the cluster schema at /usr/share/cluster/cluster.rng during startup time and when a configuration is reloaded. Also, you can validate a cluster configuration any time by using the ccs_config_validate command.

An annotated schema is available for viewing at /usr/share/doc/cman-X.Y.ZZ/cluster_conf.html (for example /usr/share/doc/cman-3.0.12/cluster_conf.html).

Configuration validation checks for the following basic errors:

XML validity — Checks that the configuration file is a valid XML file.
Configuration options — Checks to make sure that options (XML elements and attributes) are valid.
Option values — Checks that the options contain valid data (limited).