FUJITSU C150-E049-02EN - Manual (Page 64)

M3099GX/GH OEM Manual 3-31
INTERFACE
Superseding Reservations
An initiator that currntly has a logical unit reserved may modify the
current reservation by issuing another RESERVE UNIT command
to the same logical unit. The superseding reservation shall release the
current reservation if the superseding reservation request is granted.
If the superseding resrvation cannot be granted because of conflicts
with a previous reservation (other than the current reservation), then
the target shall return RESERVATION CONFLICT status.
See ANSI SCSI-2 9.2.10.2 for details.
RELEASE UNIT Command
The RELEASE UNIT command (Table 3.9) is used to release
previously reserved logical units for the requesting initiator to
another specified SCSI device.
Table 3.9 RELEASE UNIT Command
Bit
Byte
0
1
2
3
4
5
7 6 5 3 2 1 0
Operation Code (17h)
Reserved
Reserved
Reserved
Control
Logical Unit Number 3rdPty Third Party Device ID Reserved
4
The RESERVE UNIT and RELEASE UNIT commands provide the
basic mechanism for contention resolution in multiple-initiator
systems.
If a valid reservation exists for the I_T_L nexus, the target shall
release the reservation and return GOOD status.
#03.pm5 98.2.22, 1:31 PM 31