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The cluster configuration tool system-config-cluster can be used to change the name of a cluster. However, doing this will prevent GFS filesystems from mounting, as the name of the cluster is used when the GFS filesystem is created.

The following error occurs if an attempt to mount a GFS filesystem is made after the name of the cluster is changed:

May 16 15:43:17 rh4cluster2 kernel: GFS: Trying to join cluster "lock_dlm", "rh4cluster:gfsNEW01"
May 16 15:43:17 rh4cluster2 kernel: lock_dlm: cman cluster name "newname" does not match file system cluster name "rh4cluster"
May 16 15:43:17 rh4cluster2 kernel: lock_dlm: init_cluster error -1
May 16 15:43:17 rh4cluster2 kernel: GFS: can't mount proto = lock_dlm, table = rh4cluster:gfsNEW01, hostdata = 

To correct this problem, the superblock of the GFS filesystem must be altered so that it contains the correct cluster name. The following command should be issued from one node in the cluster:

gfs_tool sb /path/to/device table new_cluster_name:filesystem_name

Where "/path/to/device" is the location of the filesystem (for example, /dev/VolGroup00/LogVol00), and "new_cluster_name" is whatever the cluster name was changed to. The last argument "filestem_name" refers to the name the filesystem was given at the time it was created. The name can remain the same, or it can be changed at the same time the cluster name is changed.

After running the above command, the GFS filesystem should mount as expected.