My Windows Server 2012 R2 Essentials server has started throwing the same error each time during daily backups, each backup has this error in the failed items backup log:
Error in backup of E:\System Volume Information\SRM\quota.md during write: Error [0x80070020] The process cannot access the file because it is being used by another process.
E: is a parity Storage Space. Each backup status is now incomplete but otherwise all other data appears to have been backed up. It does mean however that each backup task now runs a full backup on E: rather than incremental because of the "failure" status.
I tried using the Dashboard to exclude this path from backup however I just got a different error related to items under the System Volume Information folder. There seems to be a underlying issue as to why System Volume Information is now causing problems, but I'm not sure what it is. As far as I'm aware I am not using any Quota functionality unless Windows itself is doing something I'm not aware of.
Additionally the core configuration of the server has not changed, so I am slightly confused as to why the backup is now "failing".
While this doesn't explain why
0x80070020error occurs. The problem appears to be whenwbadmin.exeis provided an exclude flag. Running whole backup of theE:/storage space completed successfully.A similar problem was reported related to WSUS:
https://social.technet.microsoft.com/Forums/windowsserver/en-US/a9ec7dc7-2f87-4a1e-bebe-e1717b4b1565/cannot-backup-dsystem-volume-informationsrmquotamd?forum=winservergen
Ultimately for whatever reason Windows doesn't like the exclude option in the backup now. It had worked fine up until a few weeks ago and the only thing that would of changed would of been the amount of data being excluded overtime.
I suspect this is a bug in Windows.