Sun Oracle Storage Tek T10000, Reference Manual

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E20425-01 • Chapter 4 Commands 145
Persistent Reserve Out Command
Registering a Reservation Key
An initiator must register a key before performing any other Persistent
Reserve Out commands. To register a key, the initiator sends a Persistent
Reserve Out command with the Service Action field set to Register (0h), and
the Parameter List length set to 18h. The Scope and Type fields will be
ignored. In the parameter data, the Reservation Key field is set to 0h, the
Service Action Reservation Key is set to the desired key value and the APTPL
bit to 0h. If the initiator is already registered, the key can be changed by
sending the same command with the Reservation Key field set to the current
reserved key.
A key may be registered without regard to whether one had been previously
established by setting the Service Action field to Register and Ignore (06h).
Once an initiator has registered a key, it becomes a registered initiator and
can perform other Persistent Reserve functions.
Creating a Persistent Reservation
To create a Persistent Reservation, a registered initiator sends a Persistent
Reserve Out command with a Service Action field of Reserve (01h). The
Scope field is set to 0, the Type field to Exclusive Access (03h) or Exclusive
Access Registrants Only (06h), and the Parameter List Length to 18h. In the
parameter data, the Reservation Key is set to the currently registered key for
this initiator, the Service Action Reservation Key field is ignored, and the
APTPL bit is set to zero.
A Type field of Exclusive Access will reserve the device for this initiator only. A
Type field of Exclusive Access, Registrants Only will allow access by all
registered initiators.
When a reservation of type Exclusive Access, Registrants Only is cleared, a
unit attention condition is established for the initiators holding the reservation.
Releasing a Persistent Reservation
To release a Persistent Reservation, a registered initiator sends a Persistent
Reserve Out command with a Service Action field of Release (02h). The
Scope and Type fields must match those used when making the reservation.
The Parameter List Length is set to 18h. In the parameter data, the
Reservation Key is set to the currently registered key for this initiator, the
Service Action Reservation Key field is ignored and the APTPL bit is set to
zero.
When a reservation of type Exclusive Access, Registrants Only is released, a
unit attention condition is established for the other registered initiators.