At the NSD Node, I issue the command
# mmaddnode -N node1 Thu Jul 23 13:40:12 SGT 2015: mmaddnode: Processing node node1 mmaddnode: Node node1 was not added to the cluster. The node appears to already belong to a GPFS cluster. mmaddnode: mmaddnode quitting. None of the specified nodes are valid. mmaddnode: Command failed. Examine previous error messages to determine cause.
If we do a mmcluster, the node is not around in the cluster
# mmcluster |grep node1
If the node is not in the cluster, issue this command on the client node that could not be added:
# mmdelnode -f mmdelnode: All GPFS configuration files on node goldsvr1 have been removed.
Reissue the mmaddnode command.