Existing snapshot handling parameter (WMI)
This option specifies the action that NetBackup takes when a NetBackup snapshot is discovered before NetBackup creates a new snapshot for the virtual machine backup. After it creates a snapshot, NetBackup usually deletes the snapshot when the backup completes.
If a virtual machine snapshot exists that NetBackup previously created, NetBackup removes the old snapshot, creates an updated snapshot, and proceeds with the virtual machine backup.
See Hyper-V - Advanced attributes.
If a virtual machine snapshot (checkpoint) exists that a NetBackup backup previously created for a WMI backup, NetBackup aborts the job for that virtual machine only. This option is the default operation of NetBackup.
You can use the NetBackup nbhypervtool.exe tool to remove NetBackup snapshots of the virtual machine. This tool is in the following location on the Hyper-V server:
install_path\NetBackup\bin\nbhypervtool.exe
For example, to remove a snapshot by specifying the name of the VM:
nbhypervtool.exe deleteNbuCheckpoints -vmname VM_name
Where VM_name is the name of the VM.
To remove a snapshot by specifying the GUID of the VM:
nbhypervtool.exe deleteNbuCheckpoints -vmguid VM_guid
Where VM_guid is the GUID of the VM.