Maxtor 10K V - Manual (Page 143)

Maxtor Atlas 10K V 5-85
04h Pre-empt
A PERSISTENT RESERVATION OUT command with a successful Pre-empt service ac-
tion removes all persistent reservations for all initiators that have been registered with the
Service action Reservation key specified in the PERSISTENT RESERVATION OUT com-
mand’s parameter list. A persistent reservation is also established for the pre-empting initi-
ator. Any commands from any initiator that have been accepted by the device server as non-
conflicting continue their normal executions. If a PERSISTENT RESERVATION OUT
command is sent that specifies a Pre-empt service action and no persistent reservation exists
for the initiator identified by the Service action Reservation key, it is not an error condition.
A UNIT ATTENTION condition is established for the pre-empted initiators. The sense key
is set to UNIT ATTENTION; the additional sense data is set to RESERVATIONS PRE-
EMPTED. Commands that follow are subject to the persistent reservation restrictions set by
the pre-empting initiator.
The persistent reservation thus created by the pre-empting initiator is defined by the Scope
and Type fields of the PERSISTENT RESERVATION OUT command and the correspond-
ing fields of the command’s parameter list.
The registration keys for the pre-empted initiators are removed by the Pre-empt service ac-
tion; the reservation key for an initiator that has performed a Pre-empt service action with
its own Reservation key specified in the Service action Reservation key remains unchanged,
although all other specified releasing actions and reservation actions are performed.
Note that persistent reservations are not superseded by a new persistent reservation from any
initiator except by the execution of a PERSISTENT RESERVATION OUT that specifies
either the Pre-empt or the Pre-empt and Clear service actions. New persistent reservations
that do not conflict with an existing persistent reservation execute normally. The persistent
reservation of a logical unit or extents having the same Type value are permitted if no con-
flicting persistent reservations other than the reservations being pre-empted are held by an-
other initiator.
Note: Service Action (Code) 4 is not supported by Atlas 10K V.
Code Name Description