RESERVE | 6.Command Specification |
6.23.RESERVE (6/10) 16h and 56h
Table 6-92: RESERVE (6) CDB format
Bit | 7 | 6 | 5 | 4 |
| 3 |
| 2 | 1 | 0 |
Byte |
|
|
|
|
|
|
|
|
|
|
0 |
|
|
| Operation | Code (16h) |
|
|
|
| |
1 |
| Reserved |
|
|
|
|
| Obsolete |
|
|
2 |
|
|
| Obsolete |
|
|
|
|
| |
3 |
|
|
| Reserved |
|
|
|
|
| |
4 |
|
|
| Reserved |
|
|
|
|
| |
5 |
|
|
| Control |
|
|
|
|
| |
|
| Table |
|
|
| |||||
|
|
|
|
|
|
|
|
|
|
|
Bit | 7 | 6 | 5 | 4 |
| 3 |
| 2 | 1 | 0 |
Byte |
|
|
|
|
|
|
|
|
|
|
0 |
|
|
| Operation | Code (56h) |
|
|
|
| |
1 |
| Reserved |
| 3rdPty |
| Reserved | Long ID | Reserved | ||
2 |
|
|
| Obsolete |
|
|
|
|
| |
3 |
|
|
| Third Party Device ID |
|
|
| |||
4 |
|
|
| Reserved |
|
|
|
|
| |
5 |
|
|
| Reserved |
|
|
|
|
| |
6 |
|
|
| Reserved |
|
|
|
|
| |
|
|
| Parameter List Length |
|
|
| ||||
9 |
|
|
| Control |
|
|
|
|
| |
The RESERVE (6/10) command reserves the logical unit for exclusive use by the requesting initiator or one other specified SCSI device (third party). The RELEASE (6/10) command is used to release the logical unit if it was reserved by the requesting initiator using a RESERVE (6/10) command and is still in the reserved state.
See PERSISTENT RESERVE OUT/IN for an alternate reservation system. The PERSISTENT RESERVE OUT command cannot be used to release a reservation generated by the RESERVE (6/10) commands.
Third party reservation management operations are only allowed using RESERVE (10) and RELEASE (10). Logical unit reservation management operations are allowed using RESERVE (6/10) and RELEASE (6/10). The reservation remains in effect until one of the following conditions is met:
-The initiator that made the reservation sends another RESERVE command.
-The logical unit is released by a RELEASE (6/10) command from the same initiator.
-The logical unit in a third party reservation is released by a RELEASE (10) command from the same initiator.
-A TARGET RESET or LOGICAL UNIT RESET Task Management function is received from any initiator.
The occurrence of the last two conditions is indicated by the logical unit returning a CHECK CONDITION status with a sense key of UNIT ATTENTION on the next command following the condition.
It is not an error for an initiator to issue a new RESERVE (6/10) command to the logical unit when the logical unit is currently reserved by that same initiator. If the logical unit has previously been reserved by another initiator, then the logical unit terminates the command with RESERVATION CONFLICT status.
If, after honoring the reservation, any other initiator then attempts to perform any command except INQUIRY, REQUEST SENSE, REPORT LUNS or RELEASE, then the command is rejected with a RESERVATION CONFLICT status. A RELEASE command issued by another initiator will be ignored by that reserved logical unit.
SONY |
