Certainly current Commvault DDB is stored in files, on a NTFS disk in our case. We've stopped services and copied the files between physical disks several times. Commvault only tends to care about drive letters/paths for both the DDB and block datastores. I assume you are using a RDM disk presented to a Windows VM running on ESXi? I'm not sure how Peer Motion handles RDMs but I presume it's doing all the copies at a block level, I wouldn't imagine a problem. If worried just mount both disks in the VM, copy the file structure across, do a binary file compare to be sure, swap the drive letters over and restart Commvault.