142 Product Manual - Disc Drive SCSI-2/SCSI-3 Interface (Vol. 2; Ver. 2), Rev. E
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5.2.1.9
Release Command (17h)
The Release command (Table 5.2.1-17) is used to release previously reserved drives. It is not an error for an
initiator to attempt to release a reservation that is not currently active. In this case, the drive returns Good
status without altering any other reservation.
This command is implemented by the disc drive for an Entire Unit Release with Third Party Release sup-
ported and with the disc drive specific parameters listed in Table 5.2.1-17.
Table 5.2.1-17. Release Command
Bit
7
6
5
4
3
2
1
0
Byte(s)
0
0
0
0
1
0
1
1
1
1
Logical Unit No.
3rd
Third Party Dev. ID
Extent
0
0
0 Pty
[2]
[3]
[1]
[2]
2
Reservation Identification
0
0
0
0
0
0
0
0 [4]
3
Reserved
0
0
0
0
0
0
0
0
4
Reserved
0
0
0
0
0
0
0
0
5
0
0
0
0
0
0 Flag Link [5]
Notes.
[1] In the CDB the LUN must be zero.
[2] Same as Note 2 for Reserve Command, Table 5.2.1-16.
[3] The Extent bit must be zero, if not supported by the drive. See drive Product Manual, section “SCSI
Interface commands supported”.
[4] Must be zero if not supported by the drive. See drive Product Manual, section “SCSI Interface com-
mands supported”. (see also paragraphs 5.2.1.8.1, 5.2.1.8.2).
[5] See “Control Byte” paragraph 4.2.6.
5.2.1.9.1
Logical Unit Release
If the extent bit is zero, the Release command shall cause the disc drive to terminate all reservations from the
initiator to the disc drive.
5.2.1.9.2
Extent Release
The disc drive may not support extent reservations, in which case this bit must always be zero. Since the
Reservation Identification byte is valid only for extent reservations, the disc drive ignores this byte ignores
this byte when it does not support extent release. Check the drive Product Manual section “SCSI Interface
commands supported” for support of this command.
