Reserve (56) - Hitachi HUS151473VL3800 - Ultrastar 73.4 GB Hard Drive Specifications

17.30 RESERVE (56)

Table 142: RESERVE (56)
Byte
7
0
1 Reserved = 0
2
3
4-6
(MSB)
7-8
9 VU = 0
The RESERVE command is used to reserve a LUN 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 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• the reservation is superseded by another valid Reserve command from the Initiator that made the reservation.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 Target Reset message is received from any Initiator.
• a power off/on cycle 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 Ini-
tiator 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 Target responds with a RESERVATION CONFLICT.
Hitachi Confidential
6 5 4
Command Code = 57h
3rdPty
Reservation Identification
Third Pay Device ID
Reserved = 0
Extent List Length = 0
Reserved = 0
Hitachi Ultrastar 15K147 SCSI Hard Disk Drive Specification
Bit
3 2
Reserved
182
1 0
Ext=0
(LSB)
FLAG LINK