@unomagan Hello again.
For this you will need to ensure that your vmware has allocated a unique serial to all Rockstor drives, in this case it’s the system drive that is affected but they must all have a unique serial in order that Rockstor can track them. All real drives meet this criteria but unfortunately not all virtual ones do. We have a pending documentation issue to address this in our Minimum system requirements section of the official docs:
Hope that helps. The Vmware docs should help to address this short fall and allow for the possibility for Rockstor to accurately track disks even when they have no file system on.