Hi [NAME]  I apologize for the delayed response.  Are you using the current csi-powerscale 1.6 version. If you are using 1.5 driver, kindly try this: Example : kubectl patch daemonset isilon-node -n isilon -p ‘{“spec”: {“template”: {“spec”:{“dnsPolicy”: “ClusterFirst”}}}}’
In csi-powerscale up through 1.4.0, NFS clients would be entered using the node FQDN if resolvable. It seems in 1.5.0, this has changed again and now entries are added using just the IP. This is fine, but it caused an issue with existing volumes, especially single-writer volumes. Volumes attached at the time of upgrade stay attached, but when they are detatched/un-mounted, the existing FQDN client entry is not removed from the export. Then, the next mount attempt will fail: My guess is the 1.5.0 version is now only looking for the IP to remove, and so doesn't clean up the FQDN entry that was originally added by 1.4.0? Another issue I've noticed is that "localhost" is also being added to the client lists on the export. And localhost is left behind on the export when the volume un-mounts.
csi-powerscale 1.5.0 NFS client entry changes