User's Manual

DLT4000 SCSI Interface
DLT4000/DLT4500/DLT4700 Cartridge Tape Subsystem 8-113
SCSI device specified in the Third-Party Device ID field. The drive preserves the
reservation until any one of the four conditions mentioned above occurs. The drive
ignores any attempt made by any other initiator to release the reservation and returns a
GOOD status.
An initiator that holds a current reservation may modify that reservation (for example,
to switch third-parties) by issuing another RESERVE UNIT to the drive.
8.4.19.1 Medium Changer Considerations
The optional Element reservation feature defined for Medium Changer devices in
SCSI-2 is not supported, so the RESERVE command is defined the same as for the
tape drive: Only the whole loader unit can be reserved. This is separate from a
reservation of the tape drive.
The RESERVE/RELEASE commands operate on a LUN basis; so the Medium
Changer and Tape Drive are generally handled as different devices. But in the case of
a reserved drive LUN, a MOVE MEDIUM command issued to the loader LUN can
not insert/remove a cartridge on the drive, unless the drive is reserved by the same
initiator.