Quantum DLT 8000 Product Manual page 301

PERSISTENT RESERVATION OUT Command (5Fh) (continued)
Table 5-69 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 This field contains information needed for 3 service actions: the Register service
Reservation Key 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 If the Scope is an Extent reservation, this field contains the Logical Block Address
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.
Quantum DLT 8000 Tape System
SCSI Commands
5-157