Must run full job again after changing tape to disk backup

[Kimmy_Shun]

In BE15, I run the full job with autoloader tape backup once and successfully(without run diff job).Since there is problem with tape backup, then I changed the full and diff to disk storage backup, I cannot run diff without run the full job again. Please refer to attached screen. It is the same job, and I only changed the backup media, why I have to run the full job again? If so, when there is problem with diff job on tape backup, we have to run full again and then we can run diff job on disk storage. But in BE2010 R2, we don't have this problem. We can run full job on tape, and then change diff backup to disk backup. Thanks.

[VJware]

This is expected behavior from BE 2012 and onwards.

Disk uses DLM (Data Lifecycle Management) to manage backup sets, whereas Tape uses Media Sets. If the Diff to Disk is run without a Full, DLM rules would not work properly. Secondly, one can also face issues during restore as you would need different media (tape and disk) both present at the same time.

[Kimmy_Shun]

Does that mean if the media set set to keep 2 weeks, when I changed the backup from autoloader to disk, there must be a full disk backup wthin two weeks which is not expired. And then when I changed the disk backup to tape in 1 week, I don't have to run once full on tape because there is full on tape before and within 2 weeks? Or I have to run once full backup on tape after change back?Thanks

[VJware]

Simply put, if running a chain (i.e. Full and Incr / Diff), its preferable that they run to the same storage device type. If changing any settings / device, then best to restart the full followed by the incr / diff.