WS2012 R2 Hyper-V host fully patched. Server is backed up nightly to USB disks via WSB.
Backups worked flawlessly for many months. Then a recurring problem started a few months ago. Took a while, but I've found a pattern that leads me to suspect a WSB database problem.
The backup will work for 2-4 weeks. Then backups start failing with these messages:
- Drive F: (VHDX files): "The mounted backup volume is inaccessible. Please retry the operation."
- System State: "There was a failure in preparing the backup image of one of the volumes in the backup set. Detailed error: The mounted backup volume is inaccessible. Please retry the operation."
Thereafter, all backups to that disk will fail with those 2 errors until the disk is removed as a backup destination and re-added (with format). Then the cycle repeats: Works 2-4 weeks, then won't work until the disk is set up as a new backup destination.
This happened with multiple disks, but just to make sure I didn't have multiple disk failures, I bought a new disk, which worked perfectly for 3.5 weeks. The failures began last night.
I think this rules out a problem with the source disk, because it's the destination disk format that always fixes it. For that matter, the source disk is mirrored and Dell OMSA doesn't detect any problems. But I also don't believe I have 4 failing USB disks, including one that's a month old. And that's why I think it's the database.
If that all seems reasonable, is there a way to rebuild the database from the USB disks? Or if necessary, delete it and let WSB start over from scratch?