Backup fails to perform snapshot on virtual machines for Hyper-V. The VSS writers status are all stable and the Event logs don't show any error. The "Error creating VSS snapshot" is only seen in NetVault Backup.
As per Microsoft, Microsoft Volume Shadow Copy Service uses the following hierarchy to select the provider to use during shadow copy creation
1. Hardware provider
2. Software provider
3. System provider
NetVault needs to use the Microsoft software provider to take the snapshot. Make the following registry settings to force the VSS servicer to use the software provider in the guest virtual machine.
1. Click Start, click Run, type regedit and then click OK.
2. Locate the following registry subkey and then right-click it:
HKey_Local_Machine\SYSTEM\CurrentControlSet\Control\BackupRestore
3. Point to New, and then click DWORD Value.
4. Type UseMicrosoftProvider as the name for the new DWORD value, and then press ENTER.
5. Double-click UseMicrosoftProvider. To enable, type 1 in the Value box. To disable, type 0 in the Value box
6. Reboot for the changes to take effect
