Hi, Shawn, sorry to be slow in responding, but as you
pointed out, it's vague in the standads that apply (FCP-3/4 and FC-LS), and I
ahd to struggle to find anything. In the end, I came to the same conclusion as
Kevin Butt about intent.
There is some hint in both standards that a PLOGI in the
presense of an existing N_Port Login is traumatic: In FCP-4 table 7, the columns
for PLOGI and PRLI are the same as the ones for LOGO and
PRLO.
In FC-LS concerning PLOGI, the third paragraph of
subclause 6.3.2.1 requires treatment of new Sequences "as though a
Logout had been performed". From the standpoint of FC-LS, this is essentially
equivalent to an implicit logout, since FC-LS and FC-FS-3 specify no persistent
behavior that is not either renegotiated by PLOGI or reflected in the collection
of open Sequences.
Concerning PRLI, FC-LS insists on the next to last
paragraph on page 180 (printed numbering) that it does NOT imply Process
Logout; however, the last paragraph suggests the iimpact is similar if Service
Parameters are changed. FCP-3/4 would appear to override this, at least in
part.
You're right that some clarification would be nice. I
suspect that FC-LS-2 needs to explicitly say that a PLOGI causes implicit logout
of any existing N_Port Login with the same N_Port, and FCP-4 should say that
PRLI causes I_T nexus loss if it changes existing FCP-4 Service
Parameters. Others on this reflector may be able to make a better
statement. Would you like to propose text for FCP-4 and/or FC-LS-2?
Would you like me to?
- bob nixon (secretary for FCP-4 and
FC-LS-2)
A big thank you to all who responded! I was just wondering if
anyone may know where I can reference the situations which cause an implicit
LOGO/PRLO, or maybe is this a better question to ask T11? FC-LS-2 section
6.4.4 seems to be vague on the issue, and doesn't mention this
case.
Thanks,
--
Shawn Authement
Sr. Software Engineer
Texas Memory Systems, Inc.
Shawn.Authement@texmemsys.com
ph: +1.713.266.3200
Kevin D Butt wrote:
Shawn,
Yes, when an N_Port performs a PLOGI/PRLI it logs in
again. This can be viewed as an implicit LOGO/PRLO and as stated in 4.11
of FCP-4 (http://www.t10.org/ftp/t10/drafts/fcp4/fcp4r01.pdf) this generates an I_T nexus loss notification.
Regards,
Kevin D. Butt
SCSI & Fibre Channel Architect, Tape
Firmware
MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
Tel: 520-799-2869 /
520-799-5280
Fax: 520-799-2723 (T/L:321)
Email address: kdbutt@us.ibm.com
http://www-03.ibm.com/servers/storage/
* From the T10 Reflector (t10@t10.org),
posted by:
* Shawn Authement <Shawn.Authement@texmemsys.com>
*
All,
I
am currently researching device behavior with respect to N_Port login
and
was wondering if anyone can provide clarification.
Q: If an
already-logged-in N_Port performs login again (via PLOGI), is
this
considered an I_T nexus loss as defined by SAM-3, 6.3.4?
The ENDL Fibre
Channel Bench Reference implies that re-Login causes an
implicit Logout.
However, I cannot find any supporting information in
either the
FCP-3 for FC-LS specifications. My goal is to ultimately
determine
whether a SCSI Target Port should set a Unit Attention if a
SCSI Initiator
Port re-logs in.
Thank you for your your help!
--
Shawn
Authement
Sr. Software Engineer
Texas Memory Systems, Inc.
Shawn.Authement@texmemsys.com
ph:
+1.713.266.3200
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