This issue can occur if the NFS server is removed without removing the NFS datastore. Re-adding the NFS server does not refresh the datastore mount.
Resolution
To resolve this issue, remove and re-add the datastore via the command line.
Caution: Before performing any steps in this resolution, ensure that there are no objects registered on the NFS you are trying to unmount. For more information, see:
NOTE This operation does not delete the information on the share, it unmounts the share from the host. If the NFS datastore is being used by either a virtual machine or a third party script, you may see this error:
Error performing operation: NFS Error: Unable to Unmount filesystem: Busy.
If you see this error, refer to the Caution section above
Note: After validation, if no active VM or data and step 2 command not working then please use following command to remove datastore
NOTE NFS server host names and mount points are case-sensitive. Be sure to consistently use the same case across different hosts that mount the same datastore.
NFS 4.1:
To remove a datastore:
To list the mounted datastores on the host:
# esxcli storage nfs41 list
Make a note of the NFS datastore from step 1. Run this command to delete the NFS mount:
NOTE This operation does not delete the information on the share, it unmounts the share from the host. If the NFS datastore is being used by either a virtual machine or a third party script, you may see this error:
Error performing operation: NFS Error: Unable to Unmount filesystem: Busy.
If you see this error, refer to the Caution section above
Note: After validation, if no active VM or data and step 2 command not working then please use following command to remove datastore