"An unknown error occurred" on some backups

[AlexG2490]

I'm having an intermittent backup failure on my nightly backups:

Final error: 0xe00084f4 - An unknown error has occurred.
Final error category: System Errors

I have the following errors in the job log:

Storage device "CERTANCE 1" reported an error on a request to write data to media.
Error reported:
A device attached to the system is not functioning.
V-79-57344-34036 - An unknown error has occurred.


Drivers and firmware are up to date. I deleted and rediscovered the drive, and the drive itself was replaced just three weeks ago. For the first week every backup went just fine. Now, about half of them fail with the above error, and when that happens the tape that was being written to is marked as "End Marker unreadable". I would think that if there were a hardware fault with the drive, we wouldn't be able to get a good backup regularly, but we do - 2 to 3 times a week. I'm starting to keep track of which tape the backup is on when it dies, but I think it's a case of some of the tapes being bad. They've all be written to (and re-written to) many times. The IT team doesn't just want to buy tapes without some indication that they are the problem, and not a fault with the new drive. But as I said, I would think if something were seriously wrong with the new drive, we wouldn't be able to do a full complete backup without issue as often as we do (FYI, our backup totals about 1700 GB). Can anyone lend support to my theory?

I've attached the full log in case it's needed.

[Gurvinder]

try splitting the job into 2-3 parts. Make the first job to overwrite and 2nd and 3rd can append to the tapes then.

See if this helps.

Mark, this could act as a workaround in case your backup fails with this error around the same byte count.

[CraigV]

Hi Alex,

I see you're backing up your D:\FS1 Data folder. Does this contain SQL and SQL files? If so, BE ships with Active File Exclusion (AFE), and is designed to skip certain files (like *.edb/*.ldf/*.mdf etc).

To troubleshoot, I'd deselect that particular drive, and run the backup again a couple of times. If you're using the SQL agent, you're able to backup the DBs. If you need to back up this folder, consider putting in explicit exclusions for those files.

With regards to errors on tapes, you can go into the Media tab in BE, and then select a tape. It will show you the number of errors on any particular tape, and you can base your recommendation to purchase new tapes on this.

Laters!