Reference Guide

Chapter 4 SCSI Commands
PERSISTENT RESERVE OUT Command (5Fh)
DLT-S4 Interface Reference Guide 225
05h Preempt
& Abort
A PERSISTENT RESERVE OUT command with a Preempt & Abort service action
removes all persistent reservations for all initiators that have been registered with
the service action Reservation Key specified in the
PERSISTENT RESERVE OUT
command’s parameter list. It also establishes a persistent reservation for the
preempting initiator. Any commands from the initiators being preempted are
terminated as if the preempted initiator had performed an ABORT TASK
management function. If a
PERSISTENT RESERVE OUT command is sent that
specifies a Preempt & Abort service action and no persistent reservation exists for
the initiator identified by the service action Reservation Key, it is not an error
condition. If the key is registered, however, the Clear portion of the action executes
normally.
A
UNIT ATTENTION condition is established for the preempted initiators.
The Sense Key is set to
UNIT ATTENTION, the Additional Sense Code is set to
RESERVATIONS PREEMPTED. Commands that follow, and retries of commands
that timed out because they were cleared, are subject to the persistent reservation
restrictions set by the preempting initiator.
The persistent reservation the preempting initiator created is defined by the Scope
and Type fields of the
PERSISTENT RESERVE OUT command and the
corresponding fields of the command’s parameter list.
The Preempt & Abort service action clears any CA condition with the initiator that
is preempted.
The Reservation Keys for the other initiators preempted are removed by the
Preempt & Abort service action. The Reservation Key for an initiator that has sent a
Preempt & Abort action with its own Reservation Key specified in the service
action’s Reservation Key remains unchanged, although all other specified clearing
actions, releasing actions, and reservation actions are performed.
Persistent reservations are not superseded by a new persistent reservation from
any initiator except by executing a
PERSISTENT RESERVE OUT command that
specifies either the Preempt or Preempt & Abort service action. New persistent
reservations not in conflict with an existing persistent reservation execute
normally.
06h Register
and
Ignore
Key
Behaves like the Register (00h) action except that it ignores the Reservation Key in
the parameter list and treats it as if it matched the current registration, if one exists,
for the initiator.
07h Register
and
Move
Registers the specified initiator port and moves the reservation to the initiator port.
Code Name Description