Dell PowerVault TL4000 - Manual (Page 60)

0h Persistent reservation applies to the full logical unit
1h Obsolete
2h Persistent reservation applies to the specified element
3h - Fh Reserved
Parameter List Length:
The Parameter List Length shall be set to the length of the Persistent Reserve Out Parameter List
structure.
PERSISTENT RESERVE OUT Parameter List
The format for the reservation descriptor is shown below. There shall be a reservation descriptor for the
persistent reservation, if any, present in the logical unit and a reservation descriptor for each element, if
any, having a persistent reservation.
Bit 7 6 5 4 3 2 1 0
Byte
0 (MSB) Reservation Key
7 (LSB)
8 (MSB) Service Action Reservation Key
15 (LSB)
16 (MSB) Scope-Specific Address
19 (LSB)
20 Reserved APTPL
21 Reserved
22 (MSB) Obsolete
23 (LSB)
Field descriptions:
Reservation Key:
The Reservation Key field contains a value provided by the application client to the device server
to identify the initiator that is the source of the PERSISTENT RESERVE OUT command.
Service Action Reservation Key:
For the Register, and Register and Ignore Existing Key service action, the Service Action
Reservation Key contains the new registration key to be registered. For the Preempt, and Preempt
and Abort service actions, the Service Action Reservation Key field contains the reservation key of
the persistent reservations that are being preempted. The Service Action Reservation Key field is
ignored for all other service actions.
Scope-Specific Address:
If the Scope is an Element Scope reservation, the Scope-Specific Address field shall contain the
element address (zero filled in the most significant two bytes).
APTPL:
The Activate Persist Through power Loss (APTPL) bit shall be valid only for the Register, or the
Register and Ignore Existing Key service action. In all other cases the APTPL bit shall be ignored.
3-46 TL2000 and TL4000 SCSI Reference