Optical Drive and Library SCSI-2 Command Reference

SCSI-2 Drive Command Set
Reserve Command (16H)
Chapter 22-52
Reserve Command (16H)
This command is used to reserve the drive for use by a single SCSI
initiator if and when the drive is connected to multiple initiators.
The reservation is effective until one of the following occurs:
• The Reserve initiator sends another valid Reserve Command
• The Reserve initiator releases using a Release Command
• Any initiator sends a Bus Device Reset message
• A Reset conditions occurs
Once RESERVED, other initiator commands (except Inquiry and
Request Sense) for the logical unit are rejected and result in a
"Reservation Conflict" status. A Release Command sent by another
initiator is ignored.
3rdPty A 3rd Pty bit of 1 indicates that the drive is reserved for
the SCSI device specified in the Third Party Device ID
field.
3rd Pty
Device ID 3rd Pty Device ID indicates identification of the SCSI
device for which the drive is to be reserved.
Table 2-45 Reserve Command CDB
Byte 7 6 5 4 3 2 1 0
0 Operation Code (16H)
1 Logical Unit Number
(0)
3rd
Pty
3rd Party Device ID Rsvd
(0)
2 Reserved (0)
3 Reserved (0)
4 Reserved (0)
5 Reserved (0) Flag Link