Accelerator enabled incremental backup of NetApp NAS volume
Accelerator enabled NAS-Data-Protection policy backups complete volume instead of only the incremental data. This also affects the run optimization.
This issue occurs under the following conditions:
The policy type is NAS-Data-Protection.
In the policy's Snapshot options, the value of Access Protocol is Default or NFS3.
Backup selection has NetApp NAS volumes.
The Accelerator technology optimizes a backup by sending only changed blocks over a network for backup. A two-step process is used to identify the changed files and changed blocks in these files. File attributes and index node (inode) are the key parameters to identify a change. If the files are accessed over NFS version 3, a file on a NetApp NAS volume behaves differently because of the inode numbers. The same file has different inode numbers across snapshots of the volume if accessed over NFS3. All schedules of backup are based on the snapshot that is created for the run of the policy. New snapshots with different inode numbers than the previous ones helps the accelerator to identify these files as new files. Because of this issue, all files are backed up instead of incremental data only.
To resolve this issue, avoid using NFS version 3 to access the snapshot for accelerator-enabled backups. You can change the Access Protocol to NFS4 for the affected policy. For more details, refer to the NetApp documentation.