SCSI Commands: 41BRESERVE
Page
180
3.29
RESERVE
The RESERVE command reserves the drive for exclusive use of the requesting
Initiator.
The drive reservation once established remains in effect until one of the following
occurs:
Another RESERVE command arrives from the same Initiator that requested the
current reservation. The new reservation supersedes the current one and may be
the same as the current one. Redundant use of the command is not considered an
error.
A RELEASE command arrives from the same Initiator that requested the current
reservation. The drive returns to unreserved mode.
A Bus Device Reset message (Parallel SCSI interface) or Target Reset or Logical
Unit Reset task management request (Fibre Channel interface) arrives from any
Initiator.
A Reset condition occurs.
Firmware is updated.
When the drive is reserved, it returns Reservation Conflict Status in response to
most commands received from excluded Initiators. INQUIRY, REQUEST SENSE,
Prevent Medium Removal (with a prevent bit of zero), and RELEASE commands are
accepted from any initiator.
3.29.1
RESERVE Command Descriptor Block
3.29.1.1
RESERVE(6) Command Descriptor Block
Byte
Bits
7 6 5 4 3 2 1 0
0
Operation Code (16h)
1
Ignored LUN
Reserved
2
Reserved
3
Reserved
4
Reserved
5
Control
3.29.1.2
RESERVE(6) Command Field Descriptions
Field Bytes
Bits
Description
Operation
Code
0
The Operation code for the 6-byte version of RESERVE is 16h.
Ignored
Logical
Unit
1
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.
Summary of Contents for LTO 4
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