Release Unit; Command Descriptor Blocks - Seagate Viper 200 Scsi Interface Manual

SCSI Commands

RELEASE UNIT

Command Descriptor Blocks

6-Byte Command Descriptor Block
Field Descriptions
10-byte Command Descriptor Block
The Release Unit command releases a current drive reservation, if the command is
received from the Initiator that established the reservation.
Any Release Unit command that arrives from other than the originating requester is
ignored and Good Status is returned in response to the command.
Third Party reservations are not supported.
It is not an error to attempt to release an ID that is not currently reserved to the
requesting Initiator. A reservation cannot be released if the reservation was made by
another Initiator. Other events and conditions that can cause a reservation to be
released are discussed under the Reserve Unit command.
Bits
Byte
7 6
0
1 Ignored LUN
2
3
4
5
Field Bytes Bits
Operation 0
Code
Ignored 1 5-7
Logical
Unit
Reserved
Control 5
Bits
Byte
7 6
0
1 Ignored LUN
2
3
4
5
6
7
8
9
5 4 3
Operation Code (17h)
Reserved
Reserved
Reserved
Reserved
Control
Description
The Operation code for the 6-byte version of Release Unit is 17h.
The LUN field is residual from the SCSI-1 days and is ignored.
All reserved bits must be 0.
See Control Byte Format on page 18.
5 4 3
Operation Code (57h)
Reserved
Reserved
Ignored Third Party Device ID
Reserved
Reserved
Reserved
Reserved
Reserved
Control
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2 1 0
2 1 0