Avamar: Avamar NDMP Celerra/VNX subvolume incrementals

There are times when it is necessary to back up a directory below the volume level for Celerra, VNX, and Unity systems.

To configure a sub-volume backup, modify the dataset and enter the path to the directory to be backed up.
(The path must be a directory. File backups are not supported.)

By default, the backup for any sub-volume backup is a Full - Level 0 backup. The reason for this is that if there are links from the sub-volume to somewhere outside of the sub-volume, only the link is backed up.  

A Full backup backs up the link and the data.

To force an incremental backup for these sub-volumes, use the allowsubvolumeincremental flag.

Below are the two ways to set this parameter:

• Set the parameter: [avndmp]allowsubvolumeincremental
• Set the value: true

Alternatively, modify or create an avndmp.cmd file under the client folder on the NDMP accelerator node.

For example: /usr/local/avamar/var/CLIENT_DIR/avndmp.cmd

The file should contain:

--allowsubvolumeincremental 

The first method (UI config) sets the parameter for all clients via the general dataset.

The second method (cmd file) only sets it for that one client. A full backup must be performed the first time as normal.  This should occur automatically. and subsequent backups will be incremental.