Consider the following scenario:
In this scenario, the Backup ConfigMgr Site Server task of System Center Configuration Manager 2007 SP2 fails.
Note To list all the VSS providers that are installed on the site server, use the following command. To run this command on a computer that is running Windows Server 2008 or Windows Server 2008 R2, open an elevated Command Prompt window, type the following command, and then press ENTER:
vssadmin.exe list providers
This issue occurs because an incorrect VSS provider is selected to perform the Backup ConfigMgr Site Server task.
If you're experiencing this issue we now have a hotfix available for download. See the following new KB for more details:
KB981640 - The "Backup ConfigMgr Site Server" task fails on a ConfigMgr 2007 site server
J.C. Hornbeck | System Center Knowledge Engineer