Had an interesting issue recently where we had a requirement to run 2 separate RMAN Incremental backup schedules.
The issue was that we were moving our backups from a legacy backup appliance and on to ZFS Storage Appliance (ZS).
However during the migration process we wanted to continue to run our backups on both.
The schedule looked something like this:
- Legacy level 0 backup
- ZS level 0 backup
- Legacy level 1 incremental backup
- ZS level 1 incremental backup
Can you see the problem?
By just running a conventional level 1 backup this would look for changes between now and the last backup. Therefore the legacy incremental would be an incremental backup from the last level 0 which was on ZS.
So we’d end up having to use a mixture of backups if we ever needed to restore and this definitely wasn’t what we wanted!
The solution is to use RMAN tags and the “for recover of tag” syntax on the incremental backup.
backup incremental level 0 database tag 'ZS_BACKUP' plus archivelog tag 'ZS_BACKUP'; backup incremental level 1 for recover of tag 'ZS_BACKUP' database plus archivelog tag 'ZS_BACKUP';
To restore and recover from the ZS Appliance you would then specify the tag on the restore eg.
restore database from tag='ZS_BACKUP'; recover database;
Expect to see more on ZFS Storage Appliance over the coming weeks as I get into ZFS Snapshots and Clones 🙂