Wot – no VSS writers ?

A clients backup failed and on inspection I noticed that the command “vssadmin list writers” which should report the status of the writers that support backups of various components came back blank. Yes Completely Blank !!

So that could explain the backup failure and the subsequent issue where I was unable to view the backup status either through the windows backup tool or through the SBS 2008 console as the server was running SBS 2008.

Specifically was seeing this problem

If you open the Windows Server Backup snap-in, the following error occurs: A fatal error occurred during a Windows Server Backup snap-in operation. Error details: Catastrophic failure. Close Windows Server Backup and then restart it.

and this in the event log   Log Name: Application Source: VSS Event ID: 8193 Level: Error Description: Volume Shadow Copy Service error: Unexpected error calling routine CoCreateInstance.  hr = 0x80070057.

Checking the records for this server – I noted that it had quite a few windows updates applied just before the backup failure. So a possible candidate for the problem as well.

On researching I noticed that several people had reported issues with a registry key as “This issue occurs because the registry path to Eventcls.dll is incorrect or because the registry data type for the TypeLib setting is incorrect.”

The resolution came from Microsoft As always backup the registry before you do anything !!

1. Click Start, type regedit in the Start Search box, and then press ENTER.

2. Locate and then click the following registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\EventSystem\{26c409cc-ae86-11d1-b616-00805fc79216}\EventClasses\{FAF53CC4-BD73-4E36-83F1-2B23F46E513E}-{00000000-0000-0000-0000-000000000000}-{00000000-0000-0000-0000-000000000000}

3. Locate the TypeLib registry value. NOTE The registry type of TypeLib should be shown as REG_EXPAND_SZ. If that is not the case, you have to delete the key, and then you have to recreate the key. To do this, follow these two steps: a. Select the TypeLib registry value, and then delete it. b. Create a new Expandable String Value, and then name it TypeLib.

4. Double-click the TypeLib registry value. In the Value Data box, type %systemroot%\system32\EVENTCLS.DLL, and then click OK.

[ Specifically in my case this was set to c:\\EVENTCLS.dll ]

5. Close Regedit.

6. Click Start, type services.msc in the Start Search box, and hit Enter.

7. Right-click the following services one at a time and click Restart:

• COM+ Event System [ note a lot of services can depend on this so make sure you are prepared for them to close !!]

• Volume Shadow Copy

8. Close the Services snap-in. 9. Open an elevated command prompt, type vssadmin list writers, and then hit ENTER. 10. Verify that the VSS writers are now listed.