First of all I'll give a short summary about the goal we want to achieve.
We use VMware as hypervisor, where I have created some folders (with virtual machines) which I want to backup to a NAS and tape library device.
The idea is to have 14 restore points on the NAS (which is always online) and we have a pool of tapes (we want to be able to restore up to 10 weeks) which are stored externally.
I've configured a daily backup job which is creating an active full backup on Tuesday evening (14 restore points on disk) with a secondary target to tape. The rest of the week are incremental backups which should be copied to tape as well.
I use one media pool with all the tapes assigned to this media pool. I configured the retention for this media pool as 'protect data for 8 weeks' (I'm not sure if I can set this to 10 weeks because active full backup finishes somewhere wednesday in the morning and offload to tape can only start afterwards so I don't have 10 full weeks between the end point of the retention period and the starting point).
Media set is configured to automatically create a new media set every wednesday at 1:00 (just before the offload of the active full backup is starting)
As expected, immediately after the active full backup on Tuesday evening, this backup file (daily backup.vbk) is written to tape and the following days, the incremental backup file (daily backup.vib) is written to tape as well.
The problem I have:
The vbk file and the vib files of the previous week are written to tapes as well which is of no use because these files were written to tapes already the previous week. This makes that I need twice as many tapes.
I really don't understand how this is possible with the above settings. Someone can help me with this?