Quantum 10K II - Manual (Page 200)

SCSI Description
Quantum Atlas 10K II Ultra160/m SCSI Hard Disk Drives 5–133
PERSISTENT RESERVATION OUT Command (5Eh) (continued)
Table 5–61 PERSISTENT RESERVATION OUT Parameter List — Field Descriptions
Data Field Description
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 RESERVATION OUT command. The device server verifies that
the Reservation Key in the PERSISTENT 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 action, the Pre-empt service action, and the Pre-empt & Clear service
action. The Service 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 Reservation Key contains the reservation key of the persistent
reservations that are being 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 device 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 contains 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
actions; 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 APTPL 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.