Symptoms
A Block backup of a Windows server fails with the following errors in the job log:9:41:16 am SNBSVH_278J Job definition resolution for node(XXXX) started
9:41:26 am SNBAPH_466J Processing backup for node (XXXX)
9:41:30 am SNBSNP3069E 3744: MsSnapShot::do_init:InitializeForBackup failed hr(0x80042302) (No Error)
9:41:30 am SNBSNP3069E 3744: Failed to Initialize the mssnap Class RC(-4)
9:41:30 am SNBSNP3069E 3744: Failed to find the VSS application componenets RC(-3) 140.146.21.82 8/8/2017 9:41:30 am SNBAPH_371W Func(discover_app::run): Exception (com.syncsort.bex.msg.bexException: <EXCEPTION CATEGORY="BEXEXCEPTION"><CODE>- 3</CODE></EXCEPTION> )
9:41:30 am SNBAPH_294J Processing jobdef, seldir list (whole node)
9:41:43 am
The application event log displays the following:
Error 8/9/2017 7:11 VSS 8193 None "Volume Shadow Copy Service error: Unexpected error calling routine CoCreateInstance. hr = 0x80070422, The service cannot be started, either because it is disabled or because it has no enabled devices associated with it.
Resolution
Verify the status of the Volume Shadow Copy service on the client node. When there is no backup running, the service should be idle (not 'Running') and set to manual. DPX, when it starts a block backup, will invoke this service in order to take the VSS snapshot. After the backup completes, the service times out and stops. In some cases, the service does not stop on its own and remains in a running state, resulting in the above error. The resolution is to stop the service and run the backup again.