Symptoms

The backup activity for a VADP backup set might report the error message "GetBackupSessionFiles failed. error: QueryChangedDiskAreas: SOAP 1.1 fault: "":ServerFaultCode [no subcode] "Error caused by file /vmfs/volumes/< Virtual Machine ID >.vmdk" Detail: /vmfs/volumes/< Virtual Machine ID >.vmdk Failed OpenListing for < vCenter \ Contanir folder\ Virtual Machine ID >" in the Event log.

As well as the warning message "Failed to get active blocks for disk2000. It will be backed up as a thick disk. QueryChangedDiskAreas: SOAP 1.1 fault: "":ServerFaultCode [no subcode] "Error caused by file /vmfs/volumes/< Virtual Machine ID >.vmdk" Detail: /vmfs/volumes/< Virtual Machine ID >.vmdk" accompanies the error above.

Note: a specific Virtual Machine location and ID is indicated in the angle brackets with the record < Virtual Machine ID >.


Cause

A VADP backup task encountered a Virtual Machine that needs a CBT reset


Workaround

The CBT reset is required.


For more information see:
How to reset CBT.
KB 2139574 "Resetting CBT for VMware vSphere".

KB 2048201 "CBT is reset after vMotion".