Notes to take care of:

1. A node being deleted cannot be the primary or secondary GPFS cluster configuration server unless you intend to delete the entire cluster. Verify this by issuing the mmlscluster command. If a node to be deleted is one of the servers and you intend to keep the cluster, issue the mmchcluster command to assign another node as a configuration server before deleting the node.
2. A node that is being deleted cannot be designated as an NSD server for any disk in the GPFS cluster, unless you intend to delete the entire cluster. Verify this by issuing the mmlsnsd command. If a node that is to be deleted is an NSD server for one or more disks, move the disks to nodes that will remain in the cluster. Issue the mmchnsd command to assign new NSD servers for those disks.

Step 1: Shutdown the Nodes before deleting

On the NSD Node

# mmshutdown -N node01

mmshutdown -N node01 
Wed May  1 01:09:51 SGT 2013: mmshutdown: Starting force unmount of GPFS file systems
Wed May  1 01:09:56 SGT 2013: mmshutdown: Shutting down GPFS daemons
node01:  Shutting down!
node01:  'shutdown' command about to kill process 10682
node01:  Unloading modules from /lib/modules/2.6.32-220.el6.x86_64/extra
node01:  Unloading module mmfs26
node01:  Unloading module mmfslinux
node01:  Unloading module tracedev
Wed May  1 01:10:04 SGT 2013: mmshutdown: Finished

Step 2: Deleting a Node

# mmdelnode -N node01

Verifying GPFS is stopped on all affected nodes ...
mmdelnode: Command successfully completed
mmdelnode: Propagating the cluster configuration data to all
affected nodes.  This is an asynchronous process.

Step 3: Confirm that the nodes has been deleted

# mmlscluster

Step 4: If you are deleting the client permanently, check and update the license file.

# mmlslicense

Summary information
---------------------
Number of nodes defined in the cluster:                         20
Number of nodes with server license designation:                 3
Number of nodes with client license designation:                17
Number of nodes still requiring server license designation:      0
Number of nodes still requiring client license designation:      0

Step 5: Update the license file.

# vim /gpfs_install/license_client.lst

Step 6: Update the license file

mmchlicense client --accept -N license_client.lst

Related Information:

1. Resolving mmremote: Unknown GPFS execution environment when issuing mmdelnode commands