6027-2366 Node nodeName is being used as an NSD
server. This may include Local Read Only Cache (LROC) storage. Review
these details and determine the NSD type by running the mmlsnsd command.
For standard NSDs, you must either delete the disk or define another
node as its server. For nodes that include LROC NSDs (local cache)
must have all the LROC NSDs removed before the node can be deleted.
Fully review the mmdelnsd command documentation
before making any changes.
Explanation
The specified node is defined as a server node for
some disk.
User response
If you are trying to delete the node from the GPFS cluster, you must either delete the disk or define another node as its server.