When trying to backup a VM on an NFS datastore (i.e. NetApp) storage, the backup immediately fails with this error. Upon inspection in the VMware client, the "Summary" page for the VM, under the "Resources" section shows that the VM has no datastore associated with it. Browsing the datastore reveals that the VM is indeed present. Downloading (via the Datastore Browser) the "{machine name}.vmx" file and opening it in a text editor reveals the VMTools .iso image mapped to IDE 0:0, as if a VMTools installation is running. However, inspecting the "Edit Settings" page of the VM within the VMWare client shows no such mapping present.
A VMTools upgrade was either never completed, or is in a hanging state on the VM. This operation by VMware places a lock on the files of the VM, and prevents the vRanger backup or replication job from knowing which datastore contains the VM's files.
In the VMWare client, create a "dummy" iso mapping by:
1) Go to the "Edit settings" page for the VM that this error pertains to.
2) Highlight the CDROM device and map the CD to an .iso image file (any .iso image will do).
3) Commit the change, then immediately go back into the "Edit Settings" page for the VM and change the CDROM device back to "Client Device".
This will remove the faulty entry from the .vmx file, and remove the VMWare lock on the VM's files. Backups should work normally after.
There are other possible causes of this error under investigation as well.
