Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification
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19.36 RESERVE (56)Table 218:RESERVE (56)
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• the reservation is superseded by another valid Reserve command from the Initiator that made the reservation.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.
3rdPty must be 0. Third Party reservations are not supported. If the 3rdPty bit is not zero, Check Condition status is returned
with a sense key of Illegal Request and additional sense code of Invalid Field in CDB.
3rd Party ID is ignored.
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.
Byte Bit
76543210
0 Command Code = 56h
1 Reserved = 0 3rdPty=0 Reserved Ext=0
2 Reservation Identification
3 Third Pay Device ID
4-6 Reserved = 0
7-8 (MSB) Extent List Length = 0
(LSB)
9 VU = 0 Reserved = 0 FLAG LINK