We had similar errors back in August 2012 on this SBS 2008 Server. Currently we have a the backup program failing with the following...
Backup unsuccessful. A Volume Shadow Copy Service operation failed. Unknown error (0x800423F4)
Running the VSSADMIN List Writers command shows the SQLServerWriter state as Failed
I tried running a backup of the System State using WBAdmin and it failed saying "Failure in a Volume Shadow Copy Service operation." It references the same Hex number as above and further states "The writer experienced a non-transient error.) I did not try to run the same backup with the Volume Shadow Copy Service disabled.
Companyweb does not run and has been that way for some time but the customer does not use Sharepoint. However, the Application Log is filled with "Windows SharePoint Services 3"
As always, your help is appreciated.
Jim Millot
Jim Millot