Correct, for the Total RDM size the script adds the capacity of the LUNs used for RDMs.
The LUNs used for datastores are not in there.
Note, there is a small overhead, in that a RDM disk also has a VMDK header file that is stored with the files of the VM on a datastore.
But the size of these RDM header VMDK files is very small.
