Reserve (56) - IBM DDRS-39130 - Ultrastar 9.1 GB Hard Drive Specifications

7.26 RESERVE (56)

Byte
7 6
0
1 LUN
2
3
4
5
6
7 (MSB)
8
9 VU = 0
Figure 108. RESERVE (56)
The Reserve command is used to reserve a L U N for an Initiator. This reservation can be either for the
Initiator sending the command or for a third party as specified by the Initiator.
Extents are not supported by the Drive. The Ext bit must be 0. If Ext bit is set to 1, Check Condition
Status is returned with a Sense Key of Illegal Request and additional sense code of Invalid Field in CDB
The Reservation Identification and Extent List Length fields are ignored.
The Reserve command requests that the entire Lun be reserved for the Initiator until;
The reservation is superseded by another valid Reserve command from the Initiator that made the reser-
vation.
The reservation is released by a Release command from the same Initiator.
A hard Reset condition occurs.
A Bus Device Reset message is received from any Initiator.
A power off/on cycle occurs.
The 3rdPty bit of 0 indicates that the Initiator that issued the the Reserve command is the Initiator for
which the L U N is reserved.
The 3rdPty bit of 1 indicates that this is a third-party reservation. The 3rd Party ID byte specifies the ID of
the third party for which the L U N is reserved. A reservation made with the 3rdPty bit of 1 and the 3rd
Party ID byte set to the Initiator that issued this Reserve command is considered equivalent to a reservation
made with the 3rdPty bit set to 0.
Bit
5 4 3
Command Code = 56h
3rdPty Reserved
Reservation Identification
Third Party Device ID
Reserved = 0
Reserved = 0
Reserved = 0
Extent List Length = 0
Reserved = 0
2 1 0
Ext = 0
(LSB)
FLAG LINK
SCSI C O M M A N D SET
139