So this is sort of a feature request/question. As most Nimblers probably know, when you evacuate a datastore in the vsphere world, the backend array has no knowledge of this removal of data (VM's). vCenter show's nothing used but Nimble still shows 1.5T used. This will lead to oversubscribing the LUN if you move VM's back on to the datastore.
Rather than forcing the customer to go through the steps to do a SCSI unset or whatever its called, it seems like the Nimble vcenter Plug-in could be used to accomplish this through the vcenter to esxi API. Click a button that zero's the unused blocks on LUN.
Am I oversimplifying?
At this point I think evacuating the datastore in vcenter, then use the plug-in to delete and re-create the datastore is probably the fastest way to the the result.