BackupExec or Backup Exec VSS issue with Windows System Path


Problem: V-79-10000-11226 – VSS Snapshot error. The Microsoft Volume Shadow Copy Service (VSS) snapshot technology selected returned: “Unexpected provider error”. Ensure that all provider services are enabled and can be started. Check the Windows Event Viewer for details.

The following volumes are dependent on resource: “C:” .

Analysis: Since this was a VSS writer issue on a Windows 2008 R2 server, the first thing I ran was “vssadmin list writers” to see what writers were failing. The failing writers were all Windows system writers like the WMI Writer. So I re-registered the writers running a batch script, but you can accomplish the same thing by restarting the server.

After ensuring the writers had no errors I ran BackupExec again and received the same error message. Having received the same error message again I stopped looking at BackupExec and started to look towards the Windows operating system.

I opened a command prompt and entered “vssadmin list writers” and received a Windows error message that the command did not exist or was not recognized as a Windows command. Since I was logged in as administrator, the vssadmin command should have been working right from the command prompt. If the command was not working from the command prompt without the full path to the command, then there was an issue with the environmental path statement in Windows.

Solution: The user had installed some software the week prior that overwrote the Windows environmental path. To resolve the issue I right clicked on My Computer – selected Properties – Advances System Settings – Advanced – Environmental Variables…  I selected the Path and clicked Edit. I then proceeded right click on the path statement, selected copy and pasted it into a notepad window.

Once the path statement was in a notepad window I could see all the %SYSTEMROOT% paths were missing. I copied them from another Windows 2008 R2 server and pasted them into the notepad window at the beginning of the path statement, ensuring there was a semicolon after the last %SYSTEMROOT% statement, then saved the path.

I logged out and back into the server, opened a command prompt and now the commands were returning values without the full command path. That night BackupExec ran fine and the issue was resolved.

Conclusion: BackupExec does not store the VSS Shadow Copy commands using the full command path, but relies upon the “%SYSTEMROOT%” path. That is fine since Backup Exec is compatible on various Windows operating systems.  I should have noticed that the “vssadmin” command needed a full path to produce results. Once that was acknowledged then changing the environmental variable path was the solution.

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