FMV1540E

Incremental backups using snapshot difference is not supported
on this version of the NetApp file server.
Explanation
 Incremental backup using Snapshot difference requires
Data ONTAP V7.3 or later. To back up unicode file names, upgrade to
Data ONTAP V7.3.3 or later or V8.1 or later.

System action
 Processing stops.

User response
 Upgrade the file server to a supported level
of Data ONTAP, then retry the operation.