The Cluster Configuration Tool automatically saves a back-up copy of your /etc/cluster.xml file whenever you save your configuration. This is useful if the cluster does not function correctly due to misconfiguration and you need to return to a previous working configuration.
The back-up configuration is stored in a file called /etc/cluster.xml.bak. If a cluster member becomes inoperable due to misconfiguration, stop cluster services on all members:
/sbin/service cluster stop
Next, overwrite the erroneous configuration with a previously saved configuration:
cp /etc/cluster.xml.bak /etc/cluster.xml
Finally, re-initialize the shared storage:
shutil -s /etc/cluster.xml