SCSI Commands: 41BRESERVE Page 1803.29 RESERVEThe RESERVE command reserves the drive for exclusive use of the requestingInitiator.The drive reservation once established remains in effect until one of the followingoccurs:Another RESERVE command arrives from the same Initiator that requested thecurrent reservation. The new reservation supersedes the current one and may bethe same as the current one. Redundant use of the command is not considered anerror.A RELEASE command arrives from the same Initiator that requested the currentreservation. The drive returns to unreserved mode.A Bus Device Reset message (Parallel SCSI interface) or Target Reset or LogicalUnit Reset task management request (Fibre Channel interface) arrives from anyInitiator.A Reset condition occurs.Firmware is updated.When the drive is reserved, it returns Reservation Conflict Status in response tomost commands received from excluded Initiators. INQUIRY, REQUEST SENSE,Prevent Medium Removal (with a prevent bit of zero), and RELEASE commands areaccepted from any initiator.3.29.1 RESERVE Command Descriptor Block3.29.1.1 RESERVE(6) Command Descriptor BlockByteBits7 6 5 4 3 2 1 00 Operation Code (16h)1 Ignored LUN Reserved2 Reserved3 Reserved4 Reserved5 Control3.29.1.2 RESERVE(6) Command Field DescriptionsField Bytes Bits DescriptionOperationCode0 The Operation code for the 6-byte version of RESERVE is 16h.IgnoredLogicalUnit1 5-7 The LUN field is vestigial from the SCSI-1 standard and is ignored.Reserved All reserved bits must be 0.Control 5 See SCSI Command Control Byte Format on page 25.
