SPC-3 target port group state transition command acceptance

Elliott, Robert (Server Storage) elliott at hp.com
Thu Feb 17 12:01:07 PST 2005


* From the T10 Reflector (t10 at t10.org), posted by:
* "Elliott, Robert (Server Storage)" <elliott at hp.com>
*
In spc3r21d, 5.8.2.5.b.D includes SET TARGET PORT GROUPS as one of the
commands that shall be supported while a target port group asymmetric
access state transition is occurring.
 
6.31 notes that if two SET TARGET PORT GROUPS are processed
concurrently, the results are vendor specific.
 
If a TPG is still transitioning (even if the SET TARGET PORT GROUPS
command that triggered it is finished), we'd like to allow that SET
TARGET PORT GROUPS commands be blocked until the initial transition
completes (even though other commands might be allowed).  Thus we'd like
to remove 5.8.2.5.b.D from the list.

The logical unit could still support the SET TARGET PORT GROUPS command
(it may support any command it wants) during a transition if it wants -
it just wouldn't be required to do so.


Excerpt from 5.8.2.5:
"During a transition between target port asymmetric access states the
device servers shall respond to a command in one of the following ways:

a) If during the transition the logical unit is inaccessible, then the
transition is performed as a single indivisible event and the device
server shall respond by either returning BUSY status, or returning CHECK
CONDITION status, with the sense key set to NOT READY, and an the sense
code set to LOGICAL UNIT NOT ACCESSIBLE, ASYMMETRIC ACCESS STATE
TRANSITION; or

b) If during the transition the target ports in a target port group are
able to access the requested logical unit, then the device server shall
support those of the following commands that it supports while in the
active/optimized asymmetric access state:

A) INQUIRY;
B) REPORT LUNS (for LUN 0);
C) REPORT TARGET PORT GROUPS;
D) SET TARGET PORT GROUPS;
E) REQUEST SENSE;
F) Echo Buffer modes of READ BUFFER; and
G) Echo Buffer modes of WRITE BUFFER.

The device server may support other commands when those commands are
routed though a target port that is transitioning between asymmetric
access states.

For those commands that are not supported during a transition, the
device server shall terminate the command with CHECK CONDITION status,
with the sense key set to NOT READY, and the additional sense code set
to LOGICAL UNIT NOT ACCESSIBLE, ASYMMETRIC ACCESS STATE TRANSITION."

-- 
Rob Elliott, elliott at hp.com 
Hewlett-Packard Industry Standard Server Storage Advanced Technology 
https://ecardfile.com/id/RobElliott 


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