A new system has been found with drives that would not respond if inserted into a few of the slots in the drawers. Any drives inserted into those slots would not report to the system.
This is in a U840 Dell storage array. This was found in an old array that was just being configured.
The drives were in the wrong slots due to a mislabeled slots in the storage array.
A drawer in the storage array was defective and replaced by Dell and the drives were moved into the correct slots.