Chapter 4 SCSI Commands
RELEASE (10) Command (57h)
DLT-S4 Interface Reference Guide
279
Table 154
RELEASE (10)
Command — Field Descriptions
If LongID is set to 1, the parameter list length is 8 bytes and the parameter
list has the following format.
Figure 140
RELEASE (10)
ID
Only Parameter List — Data
Format
Field
Description
3rdPty
Third Party Release allows an initiator to release a previously established third party
reservation. When set to 0, third-party release is not requested. When set to 1, the
drive releases the specified logical unit, but only if the initiator ID, 3rdPty bit, and
Third Party Device ID are identical to those of the
RESERVE
command that
established the reservation.
LongID
When set to 1, the Parameter List Length is 8 and the 8 bytes of the parameter list
carry the device ID of the third-party device. The drive ignores the contents of the
Third Party Device ID in the CDB (byte 3). This bit is ignored if the 3rdPty bit is not
set.
Extent
The drive supports reservations only on entire logical units. Must be set to 0.
Reservation
Identification
The drive ignores the value in this field.
Third Party
Device ID
If the Third Party Device ID value that is connected with the reservation release is
less than 255, the LongID bit may be set to 0 and the ID value can be sent in the CDB.
If the LongID bit is set to 0, the Parameter List Length field must also be set to 0. If the
Third Party Device ID value is greater than 255, the LongID bit must be set to 1.
Parameter List
Length
The contents of this field specify the length, in bytes, of the parameter list transferred
from the initiator to the drive. This field is ignored and no parameter data is
transferred unless the 3rdPty bit and LongID bits are both set.
Note:
Assuming that the RELEASE CDB is valid, the drive always returns GOOD status for this command. An
actual release only happens if the initiator has the drive reserved for itself or a third-party initiator.
Bit
Byte
7
6
5
4
3
2
1
0
0 — 7
(MSB)
Third Party Device ID
(LSB)