VMware CBT supported to tapes or not

I’m running a NetBackup 5220 Appliance (media and master server), which we’re using to backup our VMware based file servers using the NetBackup VMware policy type.

 

These backups used to run to disk but we’re having to go to tape and when doing so get the following warning in the detailed status:

 

Warning bpbrm(pid=2546) from client FS1: WRN - Missing block incremental notify script /usr/openv/netbackup/bin/post_checkpoint_notify.VMware_FileServers

 

I’ve done some reading into the issue and it’s stated that if you get this warning that incremental backups could be the same size as a full backup, as incremental block tracking is not working. That would be disastrous for us, as a full backup is 2.5TB. 

 

We don’t get this warning, or any other issues when backing up to disk. Has anyone seen this before?