Dell PowerVault ML6000 - Manual (Page 20)

10 SCSI Command Support
Element status for the Data Transfer element being cleaned will not reflect the presence of the cleaning
cartridge. It will continue to report that it is empty and accessible.
Removed Drives
Depending on how the library is configured, occasionally Data Transfer elements will be reported where no
drive is physically present at the time. This could be due to a drive that has been removed for service, or
simply a placeholder for the addition of a future drive. These empty “drive bays” will be counted and reported
via Mode Sense and Read Element Status commands. Status for such elements will indicate that they are
not accessible, and will report an ASC/ASCQ of 83/04. These elements could appear in between Data
Transfer elements that are present, creating “gaps” among the physical drives. This should not be
considered an error.