Maxtor ATLAS 10K III - Manual (Page 168)

SCSI Description
5-104 Maxtor Atlas 10K III
Table 5-123 PERSISTENT RESERVATION OUT Parameter List-Field Descriptions
Table 5-124 illustrates which fields are set by the application client and interpreted by
the device server for each Service and Scope value.
&CVC (KGNF &GUETKRVKQP
Reservation
Key
This field contains an 8-byte token that is provided by the application client to the
device server to identify which initiator is the source of the PERSISTENT RESERVA-
TION OUT command. The device server verifies that the Reservation Key in the PER-
SISTENT RESERVATION OUT command matches the Reservation Key that is
registered for the initiator from which the command is received. If there is no match,
the device server returns a RESERVATION CONFLICT status. The Reservation Key
of the initiator is valid for all Service action and Scope values.
Service Action
Reservation
Key
This field contains information needed for 3 service actions: the Register service ac-
tion, the Pre-empt service action, and the Pre-empt & Clear service action. The Ser-
vice Action Reservation Key is ignored for all other service actions.
For the Register service action, the Service Action Reservation Key field contains the
new Reservation Key to be registered.
For the Pre-empt and the Pre-empt & Clear service actions, the Service Action Res-
ervation Key contains the reservation key of the persistent reservations that are be-
ing pre-empted. For the Pre-empt and the Pre-empt & Clear actions, any failure of
the Service Action Reservation Key to match any registered keys results in the de-
vice server returning a RESERVATION CONFLICT status.
Scope-Specific
Address
If the Scope is an Extent reservation, this field contains the Logical Block Address of
the extent and the Extent Length field (bytes 22 – 23) contain the number of blocks
in the extent.
If the Scope signifies an Element reservation, the Scope-Specific Address field con-
tains the Element Address, zero-filled in the most significant bytes to fit the field; the
Extent Length is set to 0.
If the Service action is Register or Clear, or if the Scope is a Logical Unit reservation,
both the Scope-Specific Address and Extent Length fields are set to 0.
APTPL
Activate Persist Through Power Loss. This bit is valid only for Register service ac-
tions; it is ignored for all other types of service actions.
Support for APTPL set to 1 is optional. If a device server that does not support APT-
PL receives a 1 in that bit in a Register service action, it returns a CHECK CONDITION
status, with the sense key set to ILLEGAL REQUEST and additional sense data set
to INVALID FIELD IN PARAMETER LIST.
If the last valid APTPL bit value received by the device server is 0, the loss of power
in the target releases any persistent reservations and removes all reservation keys.
If the last valid APTPL bit value is 1, the logical unit retains all persistent reservations
and all reservation keys for all initiators even if power is lost and later returned. The
most recently received valid APTPL value from any initiator governs the logical unit’s
behavior in the event of a power loss.