In the process of transferring datastores from a 3PAR 7200 to a 8200. We are using the same iscsi connection.. so to vmotion we connected 2 iscsi paths to both 7200 and 8200. Once we completed and verified the storage vmotion we disconnected the remaining 2 7200 cables and plugged them to the 8200 so it now has 4 paths.
Now i didnt unmount/detach the old datastores before disconnecting the cables from the 7200 just incase our IT director had something stored in the datastore we werent made aware off (hes on vacation). Once the old datastores get disconnected from the array we cant really do anything other then delete it. My reasoning here is that if there WAS something he needed to pull from the datastore that all we would have to do is reattach 2 cables to the 7200, rescan and its up again. And if everyone was satified with the migration that we were just gonna delete the old datastores because we plan on decomissioning the older 3PAR 7200.