Reserve (16) - Fujitsu MAX3073NC - SCSI,80, Dell DC961,Hard Drive Scsi Logical Interface Specifications

3.1.11

RESERVE (16)

Bit
Byte
0
1
2
3
4
5
Together with the RELEASE command, this command controls exclusive access to the logical unit
(IDD) under a multi-initiator environment.
The IDD is reserved by this command for the INIT which issued this command or for some other SCSI
device specified in the CDB.
The INIT which issues this command must notify the IDD of its own SCSI ID when the SELECTION
phase is executed.. When the INIT's ID cannot be specified, this command is terminated with a CHECK
CONDITION status (ILLEGAL REQUEST [=5] / Initiator's SCSI ID not identified [=90-00]) without
being executed. Also, the values specified in bytes 2 to 4 of the CDB have no meaning and are
disregarded, but it is preferable that the INIT specify X '00' in these bytes.
(1) Logical unit reserve function
This command reserves the entire IDD (logical unit) for use as a special SCSI device. The reserve state
established by this command is maintained until any one of the following conditions occurs.
1) The reserve condition is changed by the INIT that issued this command (Superseding Reserve).
2) Reserve is released by a RELEASE command from the INIT that issued this command.
3) A TARGET RESET message from any INIT.
4) A RESET condition.
5) Switching the IDD's power off and on.
When an IDD is reserved for any SCSI device, if this command is issued by an INIT that doesn't have
the "Reserve Right" for that IDD, this command is terminated with a RESERVATION CONFLICT
status. See item (3) concerning the "Reserve Right."
After the Reserved status is established, a command issued by an INIT other than the SCSI device that reserved
the IDD is rejected, except an INQUIRY, REPORT LUNS, REQUEST SENSE or RELEASE command, and a
RESERVATION CONFLICT status is reported to the INIT that issued that command. The INQUIRY
REPORT LUNS, and REQUEST SENSE commands are executed normally even when the IDD is reserved for
use by another SCSI device. Also, a RELEASE command is terminated with a GOOD status, but the release
operation specified in a RELEASE command issued to the IDD by a SCSI device which does not have the
Reserve Right is disregarded.
C141-C010
7 6 5
LUN 3rd Pty
× × ×
× × ×
× × ×
0 0 0
3.1 Control/Sense Commands
4 3 2
X'16'
3rd Pty Dev ID
× × ×
× × ×
× × ×
0 0 0
1 0
0
× ×
× ×
× ×
0 Link
3-43