SAM-2 status precedence - RESERVATION CONFLICT vs. CHECK CONDITON/UNIT ATTENTION/POWER ON OCCURRED
Robert.Elliott at COMPAQ.com
Mon Mar 25 11:42:33 PST 2002
* From the T10 Reflector (t10 at t10.org), posted by:
* "Elliott, Robert" <Robert.Elliott at COMPAQ.com>
SAM-2 requires that RESERVATION CONFLICT status always have priority
over CHECK CONDITION status:
"5.3.2 Status precedence
If more than one condition applies to a completed task, the report
of a BUSY, RESERVATION CONFLICT, ACA ACTIVE or TASK SET FULL
status shall take precedence over the return of any other status
for that task."
However, after power up, most targets with a persistent reservation
stored in non-volatile memory return CHECK CONDITION status to report
a unit attention with an additional sense code of POWER ON OCCURRED
rather than report the RESERVATION CONFLICT status.
Depending on how you interpret "more than one condition applies"
this violates the SAM-2 precedence rule.
Also, SPC-3 describes how CHECK CONDITION/NOT READY is supposed
to be returned after power on until the persistent reservation
information has been loaded.
How should the SAM-2 text change to fix this?
a) change "shall" to "should"
b) add "except for a CHECK CONDITION status reporting a
UNIT ATTENTION sense key with an additional sense code with
an ASC set to 29h, or a CHECK CONDITION status reporting
a NOT READY sense key"
c) other suggestions
Rob Elliott, Compaq? Server Storage
Robert.Elliott at compaq.com
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