Study Notes

To monitor the cluster and display status at specific time intervals from a shell prompt, invoke clustat with the “-i” time option, where time specifies the number of seconds between status snapshots. The following example causes the clustat utility to display cluster status every 10 seconds
# clustat -i 10

The cluster configuration Tools automatically retains backup copies of the three most recently used configuration files (beside the currently used configuration File). Retaining the backup copies is useful if the cluster does not function correctly because of miconfiguration and you need to return to a precious working configuration.

rgmanager: manager cluster services and resoures.
system-config-cluster: contain the cluster configuration tool.
ccsd: contains the cluster configuration service daemon
magma: contains an interface library for cluster lock management
magma-plugins: contains plugins for the magma library.
cman: manager cluster membership, messaging and notification
cman-kernel: contains required cman kernal modules.
dlm: contains distributed lock managerment
dlm-kernel: contains required DLM kernel module
fence: The cluster I/O fencing system that allows cluster nodes to connect to a variety of network power switches fibre channel switches and integrited power managerment interfaces.
gulm: GuLM lock management tools/lib
iddev: contain libraries used to identify the filesytem(or volume manager) in which device is formatted.

GFS: The RedHat GFS module
GFS-kernel: GFS kernel module
gnbd: The GFS network block device module
gnbd-kernel: Kernel module for the GFS network block device
LVM2-Cluster: Cluster extensions for the logical volume manage.
gndb-kernelheader: gnbd kernel header files.