On Windows Server 2003, the Backup Exec Shadow Copy Components file system implements a Volume Shadow Copy Service (VSS) Requestor to protect critical operating system and application service data, and third party application and user data via VSS Application Writers. A VSS Application Writer is specific code within an application that participates in the Volume Shadow Copy Service framework to provide point-in-time, recovery-consistent operating system and application data. When a data protection operation of Shadow Copy Components is performed, the status of the involved VSS Application Writers must be queried to determine its status during the backup or restore.

Important: For Backup Exec for Windows Servers 9.0.4454 SP1 and earlier, once a VSS Application Writer fails, then Backup Exec is not able to clear and recover from a VSS Application Writer's initial failure. If you are running this version of Backup Exec and intend on using it with VSS, VERITAS recommends upgrading to Backup Exec for Windows Servers 9.1.4691 and Service Pack 1. A link to these updates can be found at the bottom of this document in the Related Documents section.

If VSS related issues continue to be encountered with version 9.1, please continue reading this document for further information on troubleshooting these issues.

During a Shadow Copy Components data protection operation, if a VSS Application Writer involved in the operation reports a failed status, then the data protection operation will fail  (Figure 1).

Figure 1
 

To troubleshoot this error, please perform the following steps immediately after a failed Shadow Copy Components backup has been identified:

 

1.  Open a command prompt on the server in question
 

2.  Type the following command: VSSADMIN LIST WRITERS (Figure 2)
 

Figure 2 - VSSADMIN sample output: No Errors
 

Figure 3 - VSSADMIN sample output: Errors Detected
 

 

3.  Review the output and identify the Last Error failure status for the specific VSS Application Writer that was involved in the data protection operation (Figure 3, failed "NTDS" VSS Writer). Ensure that the writers are all showing a State of "[1] Stable" and that Last Error is showing "No error."
 

If Last Error states:
 

- Retryable Error, then retrying the data protection backup operation might resolve the VSS Application Writer's initial failure
 

- Non-Retryable Error, view the Event Viewer's Application Log for information regarding the cause and possible solution to this issue.
 

 

   4. If the VSS Application Writer failure does not reset after a period of time, Backup Exec for Windows Servers continues to fail, or the native backup utility fails, then attempt to reboot the system and contact the specific company that produced the VSS Application Writer for further assistance.
 

For more information regarding what may cause the Shadow Copy Components to fail, please refer to the Microsoft Q article 826936.