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Backup to Disk Backups Failing - The process cannot access the file because it is being used by another process.

Created: 29 Sep 2009 • Updated: 21 May 2010 | 3 comments

Hello,

I am having very consistent failures on some of my backup-to-disk jobs. The exact error/failures are copied and pasted below, but essentially the jobs are failing because "The process cannot access the file because it is being used by another process". The unique part about my environment is that my backup-to-disk folder (i.e. backup destination) is enabled for Microsoft DFS replication... that way, we're able to push backup-to-disk data offsite using throttled replication. The backup jobs that fail most often with these errors are SQL backup jobs, but the failures are not limited to SQL -- we'll get occasional backups with other file/folder backups as well.

I've used Sysinternals Process Explorer to watch the B2D file handle to find out what process is "grabbing" the backup to disk file. It turns out that Backup Exec is releasing its lock on the B2D file, and the DFS Replication service (dfsr.exe) is immediately copying the file to its staging area to prepare it for replication. So, Backup Exec is releasing its lock, DFS-R starts staging the file for replication, and then Backup Exec immediately tries to re-grab the lock and fails (during the 1-2 seconds that DFS-R has it locked). I've verified that DFS-R is the competing process by stopping the DFS Replication Service and then retrying backup jobs. Of course, the backup jobs run fine with DFS-R stopped....

I've contacted Microsoft about the issue, and they are saying that this replication mechanism is by design. Backup Exec should not release its lock on the file if it is still in use, they say. In my opinion, releasing the lock on the file during the backup job seems a little strange, but if a file is locked by another process, why does BE not give it a couple seconds and try again? And then give it another couple of seconds and try again? My backup to disk files are limited to 50 MB on purpose -- this minimizes the amount of time that a B2D file is locked for staging without making them *too* small. I think that the media service should be a little more flexible -- I could very well see other processes locking B2D files momentarily (e.g. virus scanners).

I've done all the recommended troubleshooting. For example: making sure the Backup Exec service account is a domain admin; setting the RAID stripe size to 64 KB; ran a chkdsk with no errors returned; . I've also tried adjusting read & write cache settings on the backup to disk "device" -- no luck.

If anyone has any ideas, please let me know. I'm on the hunt for a fix or workaround... stopping the DFS Replication service is not a realistic option because of the number of jobs we have running and the consequent number of times DFS-R would need to be stopped and restarted throughout the day, which is an I/O-intensive operation.

Thanks!
Frank

Error detals below:

Storage device "Replicated - Tier 3" reported an error on a request to read data from media.

Error reported:
The process cannot access the file because it is being used by another process.

V-79-57344-33992 - The backup storage device has failed

*******************************************************************

Storage device "Replicated - Tier 4" reported an error on a request to read data from media.

Error reported:

The process cannot access the file because it is being used by another process.

V-79-57344-34036 - An unknown error has occurred.

 

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Frank Lesniak's picture

Dev T,

Thanks for the reply. As I already mentioned, I've checked and the Backup Exec service accounts are running as a domain admin.

Let me know if you have other ideas.

Thanks!
Frank