Reserve (16) - Fujitsu MAU3147RC SERIES Technical Manual

Command Specifications

4.1.10 RESERVE (16)

Bit
Byte
0
1
2
3
4
5
Together with the RELEASE command, this command controls exclusive access
to the logical unit (IDD) under a multi-initiator environment.
The IDD is reserved by this command for the INIT which issued this command.
The values specified in bytes 2 to 4 of the CDB have no meaning and are
disregarded, but it is preferable that the INIT specify X'00' in these bytes.
(1) Logical unit reserve function
This command reserves the entire IDD (logical unit) for use as a special SAS device.
The reserve state established by this command is maintained until any one of the
following conditions occurs.
1) Reserve is released by a RELEASE command from the INIT that issued this
command.
2) Receiving HARD RESET primitive from any INIT.
3) Switching the IDD's power off or on.
When an IDD is reserved for any SAS device, if this command is issued by an
INIT that doesn't have the "Reserve Right" for that IDD, this command is
terminated with a RESERVATION CONFLICT status.
After the Reserved status is established, a command issued by an INIT other than the
device that reserved the IDD is rejected, except an INQUIRY, REQUEST SENSE or
RELEASE command, and a RESERVATION CONFLICT status is reported to the
INIT that issued that command. A RELEASE command is the release operation
specified in a RELEASE command issued to the IDD by a SAS device which does not
have the Reserve Right is disregarded.
4-82
7 6 5
0 0 0 3rd Pty
× × ×
× × ×
× × ×
0 0 0
4 3 2
X'16'
3rd Pty Dev ID
× × ×
× × ×
× × ×
0 0 0
1 0
0
× ×
× ×
× ×
0 0
C141-C009