Reserve (6) (16H); Figure 152. Reserve - IBM IC35L036UWDY10 - Ultrastar 36.7 GB Hard Drive Specifications

8.29 RESERVE (6) (16h)

Byte
7 6
0
1 Reserved = 0
2
3 (MSB)
4
5 VU = 0

Figure 152. RESERVE (6)

The RESERVE command is used to reserve a LUN for an initiator. This reservation can be either for the
initiator which sends this command or for the third party as specified by the Initiator.
Extents are not supported by the drive. The Ext bit must be zero. If Ext bit is set to one, 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 the reservation is superseded by another valid RESERVE command from the initiator that made the
reservation.
! the reservation is released by a RELEASE command from the same initiator.
! a hard Reset condition occurs.
! a DRIVE RESET message is received from any initiator.
! a power off/on occurs.
The 3rdPty bit of zero indicates that the Initiator that issued the RESERVE command is the Initiator for
which the LUN is reserved.
The 3rdPty bit of one indicates that this is a third-party reservation. The 3rd Party ID byte specifies the ID
of the third party for which the LUN is reserved. A reservation made with the 3rdPty bit of one 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 zero.
Only the Initiator that issued the RESERVE command for a LUN may release the LUN, regardless of the
3rdPty option. This Initiator may also release the LUN by issuing another RESERVE command. This
superseding RESERVE command releases the previous reservation when the new reservation is granted.
Reservation queuing is not supported by the drive. If a LUN is reserved and a RESERVE command is
issued from a different initiator, the drive responds with a RESERVATION CONFLICT.
Bit
5 4 3
Command Code = 16h
3rdPty 3rd Party ID
Reservation Identification
Extent List Length = 0
Reserved = 0
Ultrastar 146Z10 hard disk drive specifications
2 1 0
Ext =
0
(LSB)
FLAG LINK
152