NDMP Incremental backing up unchanged data from IBM SONAS
Issue: NDMP Incremental backing up unchanged data from IBM SONAS
NBU: 188.8.131.52 Enterprise
One Master server (Win 2k3 R2), one Media server (Win 2k8 R2 SP1)
IBM SONAS gateway with NDMP v4 to XIV storage
We have an IBM SONAS remote NDMP client. All policies are configured for a monthly full backups to tape and daily differential incremental backups to DSU.
I have an issue where the differential backups are regularly backing up data that has not changed. It will regularly backup the same number of files and kb for days at a time on unchanging data. This means we are getting many TB more data backed up each day than we should.
Date Start Files KB Policy Type 2/03/2013 8:49:00 a.m. 3364 247514624 Differential-Inc 1/03/2013 1:57:22 a.m. 2881 246118843 Differential-Inc 27/02/2013 9:22:34 p.m. 2881 246118843 Differential-Inc 27/02/2013 3:31:15 a.m. 2881 246118843 Differential-Inc 26/02/2013 3:44:27 a.m. 2881 246118843 Differential-Inc 25/02/2013 1:09:34 a.m. 2881 246118843 Differential-Inc
This happens in multiple policies on multiple occasions, but apparently not consistently. It appears to act like a cumulative rather than incremental…
I've been attempting to determine if this is something to do with the NDMP levels (http://www.symantec.com/business/support/index?page=content&id=HOWTO53118 ). However, information is rather light on this subject. I assumed that NetBackup handled the levels in the background without having to pass variables in the policy? Theoretically it should be a level 2 backup each day, correct? Or is it incrementing each day up to level 9 and then having a fit? Does this mean I can’t do daily incrementals for more than 9 days in a row? Confused…
Thanks in advance,