5.33RESERVE (6) Command (16h)
The RESERVE and the RELEASE commands are used for contention resolution in
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Bit | 7 | 6 | 5 |
| 4 |
| 3 | 2 |
| 1 | 0 |
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| Operation | Code (16h) |
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1 |
| Reserved |
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| 3rdPty |
| Third Party Device ID |
| Extent | ||
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2 |
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| Reservation | Identification |
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3 - 4 |
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| Extent List Length |
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5 |
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| Control |
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Field | Description | |
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3rd Pty | When set to 1, it indicates that the Third Party Device ID field is valid. | |
| Required and used only when the 3rdPty bit is set, in which case this field specifies the SCSI ID (0 | |
| through 7 only) of the initiator to be granted the reservation of the logical unit. The drive preserves the | |
| reservation until one of the following occurs: | |
Third | • It is superseded by another valid RESERVE command from the initiator. | |
• It is released by the same initiator | ||
Party | • It is released by a TARGET RESET message from any initiator. | |
Device ID | • It is released by a hard reset condition. | |
| The drive ignores any attempt to release the reservation made by any other initiator. For example, if | |
| ID7 sends ID2 a Third Party reservation on behalf of ID6 (the target at ID2 gets reserved for the initiator | |
| ID6), then only ID7 can release the target at ID2 (using a Third Party release). ID6 cannot release the | |
| reservation even though the reservation was made on its behalf. | |
Extent | The drive supports reservations only on entire logical units. The value must be 0. | |
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Reserva- | Any value in this field is ignored by the drive. | |
tion Identi- | ||
fication |
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Extent List | Any value in this field is ignored by the drive. | |
Length | ||
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Note: The drive returns RESERVATION CONFLICT status if the unit is already reserved for another initiator. Once the reservation is honored, any command from another initiator (except INQUIRY or REQUEST SENSE) is rejected with RESERVATION CONFLICT status.
Maxtor Atlas 10K V |