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 INTERFACE with a previous reservation (other than the current reservation), then
the target shall return RESERVATION CONFLICT status.
See ANSI
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 | 7 | 6 | 5 | 4 | 3 |
| 2 | 1 | 0 |
Byte |
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0 |
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| Operation Code (17h) |
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1 | Logical Unit Number | 3rdPty | Third Party Device ID | Reserved | |||||
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2 |
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| Reserved |
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3 |
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| Reserved |
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4 |
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| Reserved |
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5 |
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| Control |
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The RESERVE UNIT and RELEASE UNIT commands provide the basic mechanism for contention resolution in
If a valid reservation exists for the I_T_L nexus, the target shall release the reservation and return GOOD status.
M3099GX/GH OEM Manual |