Troubleshooting VSS (Volume Shadow Service) Issues

Few of CloudBerry Backup users face minor issues with Volume Shadow Copy (VSS). In this article, you will get to know how to avoid and resolve possible issues with VSS.

CloudBerry Backup uses Volume Shadow Copy Service in three cases:
  • To back up files being in use at the moment of the backup;
  • For block-level backup;
  • If "Force using VSS" option is selected for a backup plan.
While running backup you can face one of the three most spread errors related to VSS:
#1 ERROR: CloudBerry Backup cannot access the file because it is being used by another process
Files can be inaccessible for three main reasons:
1) Files on network shares or mapped drives being in use can't be backed up. You can do network backups only for unlocked files. If those files are usually in use, we can only recommend installing our product locally to a machine where network files reside.
2) You may not have actual Microsoft Visual C++ installed. Download and install Microsoft Visual C++ 2010 SP1 Redistributable Package (x64) -
3) The files that failed to back up are not available for VSS. In general such files are *.ost.
List of folders that can be unavailable for VSS:
  • \softwaredistribution;
  • \backup;
  • \temp.
You can check the list of exclusions in the registry key:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\BackupRestore\FilesNotToSnapshot (go to Start | Run: regedit)
#2 ERROR: Attempted to perform an unauthorized operation
As a possible troubleshooting, try to restart the Backup Service with the Administrator account:
1) Go to “Tools” menu.
2) Click on the “Change Service account”.
3) Enter administrator account credentials and click “OK”.
The service will be restarted automatically.
#3 ERROR: Error on creating a snapshot
In some cases, you may face the situation when the service cannot load file or assembly 'AlphaVSS.60.x64.dll'.
To resolve this issue download and install Microsoft Visual C++ 2010 SP1 Redistributable Package (x64) -