Persistent Reservations Service Actions

Gerry_Houlder at Gerry_Houlder at
Fri Sep 25 10:45:30 PDT 1998

* From the T10 (formerly SCSI) Reflector (t10 at, posted by:
* Gerry_Houlder at
I disagree that the service action code values need to be changed.
Obsoleting the previously used values and creating new ones will have the
effect of obsoleting currently shipping products (both target and
initiator). The changes proposed are minuscule compared to this drastic

The change is wording from "one reservation per initiator" to "just plain
one" (for the entire LUN) has minimal impact.
 (1) In order to have one reservation per initiator, the reservations have
to be non-conflicting (this is hard to do now that extent reservations have
been obsoleted). Only the registrants only reservation types are actually
 (2) Furthermore, this change shouldn't require anyone to change their
initiator driver software (there are no new target responses for the driver
to handle).
 (3) I recall, from implementation discussions, that it was optional for
the drive to allow more than one owner for the same reservation. Updating
the ownership to the last initiator that made the request was considered an
acceptable implementation. I believe this opinion mutated to the latest
wording in 98-203 because this was a much easier implementation for the
target; since everyone was doing it that way, it was better to describe it
that way in the standard.

In summary, I prefer leaving the service action codes the way they are.

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