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 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 NetApp NAS volume behaves different because of the inode numbers. 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. A new snapshot with different inode numbers than the previous ones makes 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.