I have a client who has a server running Windows Server 2012 R2 Standard with Hyper-V running.
Whenever it tries to run a backup it fails with the two following errors:-
VSS writers inside virtual machine 'servername' failed to perform BackupComplete to its shadow copy (VSS snapshot) set: Catastrophic failure (0x8000FFFF). (Virtual machine ID xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)
The backup operation that started at '2015-05-12T19:00:35.827000000Z' has failed because the Volume Shadow Copy Service operation to create a shadow copy of the volumes being backed up failed with following error code '0x807800A1'. Please review the event details for a solution, and then rerun the backup operation once the issue is resolved.
So far I have tried re-registering the VSS dlls, setting the Volume Shadow Copy Service to Automatic and ran an SFC scan which came back ok.
Any ideas? Your help would be much appreciated!