Reserve (16) - IBM DCAS-32160 - Ultrastar 2.1 GB Hard Drive Specifications

7.25 RESERVE (16)

Byte
7 6
0
1 LUN
2
3 (MSB)
4
5 VU = 0
Figure 105. RESERVE (16)
The RESERVE command is used to reserve a L U N for an initiator. This reservation can be either for;
1. The initiator which sends this command.
2. The third party which is specified in this command.
This command results in reserving the entire L U N for the initiator until one of the following occurs:
The reservation is superseded by another valid RESERVE command from the initiator that made the
reservation.
The L U N is released by a RELEASE command from the same initiator.
A hard reset condition occurs. (A SCSI bus Reset assertion)
A BUS DEVICE RESET message is received from any initiator.
Power off/on occurs.
3rdPty bit is to indicates that :
1 This reservation is for a third party which is specified by 3rd Party ID.
0 This reservation is for the initiator itself.
3rd Party ID specifies the ID of the third party for which the L U N is reserved.
Note: The L U N may be only released by the initiator who sent the RESERVE command.
Extents must be 0. Extension is not supported by the file.
Reservation Identification is ignored.
Extent List length must be zero. Extent List length is not supported.
Bit
5 4 3
Command Code = 16h
3rdPty 3rd Party ID
Reservation Identification
Extent List Length = 0
Reserved = 0
2 1 0
Ext = 0
(LSB)
FLAG LINK
SCSI C O M M A N D SET
141