Release (10) Command (57H) - Seagate SCSI Interface Product Manual

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5.32

Release (10) command (57h)

The Reserve and Release commands provide the basic mechanism for contention resolution in multiple-initia-
tor systems. The Release (10) command (Table 148) is used to release a previously reserved logical unit or, if
the extent release option is implemented, to release previously reserved extents within a logical unit. It is not an
error for an initiator to attempt to release a reservation that is not currently valid. In this case, the drive shall
return Good status without altering any other reservation.
Table 148: Release (10) command (57h)
Bit 7
Byte
0 Operation Code (57h)
1 0
Logical Unit Number [1]
2 Reservation Identification [4]
3 3rd Party Device ID [2]
4 Reserved
5 Reserved
6 Reserved
7 Reserved
8 Reserved
9 Control Byte [5]
Notes:
[1] The Logical Unit Number must be zero.
[2] If bit 4 is zero, byte 3 is zero. If bit 4 is one, byte 3 identifies the SCSI bus ID of the device that reserves the
drive.
[3] Must be zero.
[4] Must be zero if not supported. Check with individual drive's Product Manual, Volume 1, SCSI Interface
commands supported section (see paragraph 5.35.1 of this volume).
[5] See "Control byte," paragraph 4.2.6.
For additional explanation about the Release command, see Section 5.31 and Section 5.35.5.
6 5
0 0
3rd Party [2]
SCSI Interface Product Manual, Rev. J
4 3
Reserved
2 1
Extent [3]
0
0