FMV1685E

Incremental backup operation using snapshot difference is
only available for N series/NetApp filer volumes,  is  not a NetApp volume.
Explanation
 Cannot perform NAS NFS/CIFS incremental backup
operation using snapshot difference on the mounted or mapped volume
because the volume is not a N series/NetApp filer volume.

System action
 Processing stops.

User response
  Retry the incremental backup operation by specifying
an entire NAS NFS or CIFS volume.