We are currently running BackupExec 15 on server 2008 R2 and backing up to a 14TB NAS across the network. We started with the following backup scheme...
Annual - Full - Keep 12 months
Bi Annual - Full - Keep 12 months
Weekly - Full - Keep 12 weeks
Daily - Differential - Keep 12 weeks
We are backing up five servers with similar schemes. I found that despite the storage retention settings, older backups were not getting pruned. To test this we slashed the 12 week retentions down to four. Older backups still accumulated. Am I mistaken that shortening the retention policies should also remove older backups? I can provide more info if needed.
I would recommend a read as to how DLM process works -
Juts looking at your weekly and daily settings and assuming defaukst other than yoy timings.
The weekly will run, then you will have 1 weeks worth of differenyials and as both the weejly and differential sets are set to 12 weeks, assuming the next weekly full ran sucessfully then the first weekly full set will be kept for 13 weeks plus the length of time the last differential took to run (+ up to 1 hour)
This is because the last differential forms the last recovery chain with the full and will therefore block the full from being deleted until a new recovery chain is made (by running the new full.) so if you really want a 12 week rention of the full, you should set the differential retention to 11 weeks (and make sure the next full has run)