The other day I had an issue come up with a customer where VSS (Versative Storage Server) integrated file system backups stopped working for some unknown reason. Usually, a reboot fixes these types of issues, but backups continued to fail after a reboot. I started a support call with the backup vendor and after seeing the error logs, the support tech seemed fairly sure he knew what the problem was. This error is usually caused by a malformed path within the registry. So he had me run the following commands on the server and send him the output. [more]

vssadmin list writers >> c:\writers.txt
vssadmin list providers >> c:\providers.txt
vssadmin list volumes >> c:\volumes.txt

diskshadow /L c:\shadow.txt
list writers detailed

After reviewing the text files created, he found the malformed path:

- File List: Path = c:/windows\hpsum_1327455089, Filespec = hpsumserverw32.exe

To correct the issue, I searched the registry under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\ for “c:/windows\hpsum_1327455089” and corrected the path to “c:\windows\hpsum_1327455089” . After doing this, the backup ran fine. Further research uncovered the root cause. During the last maintenance window, HP System Update Manager was used to update the HP System Management Homepage on these servers. This malformed registry key was created by HPSUM during the upgrade.