I have a server running 2012 Essentials. Windows Server Backup is set to run twice a day. The backups are being saved to a VHD file that is mounted just prior to the job and then dismounted after the job via scheduled tasks.
Some of the jobs are completing without error but others are failing saying they completed but have warnings. Here is an example.
Under the Data Transferred column for System Reserved it says 960 KB of 960 KB but under the Status column is says 1% of backup done. 960 KB of 960 KB is 100% so I don't understand why it says 1%. The C: and D: drives and System State have status of Completed but the Bare metal recovery says Backup failed to complete.
When I look on the Errors tab, for both System Reserved and Bare metal recovery the message is the same, "There was a failure while compacting the virtual hard disk on the backup location. Detailed error: The process cannot access the file because it is being used by another file."
I don't understand how this error is occurring. I'm sure it's not a case of the backup drive getting dismounted too early as the backups are incremental and take less than 1/2 hour to run but the time between mount and dismount is 3 hours.
I don't know what other process could be using the "file" nor what "file" it is referring to.
The Windows Event Logs contain even less information than the WSB details so they are of no help.
Anyone have an idea what might be going on? This is not a consistent problem as some backups run just fine including both scheduled times.
Jonathan
