You should avoid using the same LUN on more than one VMware vCenter environments. If this rule is not followed, deleting a datastore from one vCenter will cause it to appear as "dead" on the other vCenter when using the following command: esxcli storage core device list [more]

If a rescan HBA's is performed at this point, all management tools may become unresponsive.  To avoid this, the LUN needs to be marked as disabled, rescanned, then removed from the disabled list:

  1.   esxcli storage core device set -steate=off -d <NAA ID> (whatever the worldwide name is for that LUN)
  2. rescan HBA's 
  3. esxcli storage core device detached remove -d <NAA ID>

If everything is already unresponsive, "localcli" may be substituted for "esxcli."