FC-TAPE UA conditions

Joseph C. Nemeth jnemeth at concentric.net
Tue May 5 14:22:22 PDT 1998

* From the T10 (formerly SCSI) Reflector (t10 at symbios.com), posted by:
* "Joseph C. Nemeth" <jnemeth at concentric.net>
According to FC-TAPE rev 1.02, section 11.5, table 20, a
LOGO/PLOGI/PRLO/PRLI from an initiator is supposed to clear pre-existing
ACA, UA, and Deferred error conditions for a target with respect to that

If the whole system powers up, and the target happens to get on the loop
before the initiator does, does this mean that a PON UA condition will never
be reported to that initiator? That doesn't seem right.

On the other hand, suppose that a device powers up, and someone kicks the FC
cable out of the wall after about half the initiators have retrieved and
cleared the PON UA condition, but before the other half have accessed the
device. When the user plugs the cable back in, there is a huge
LIP/LOGO/PLOGI scrum, and when it's all over, the initiators may have all
changed their AL_PA addresses. If *something* isn't done about the pending
UA conditions, some of these initiators will see the PON UA twice, and some
will not see it at all.

It seems to me that any "new" initiator -- an initiator for which the
[ALPA:Port:Node] triplet has changed -- should always see a PON UA condition
|from the target, and all other UA conditions should be cleared.

ACA and Deferred error conditions, on the other hand, need to be cleared if
the faulting initiator logs out, because they prevent other initiators from
accessing the device.

Joseph C. Nemeth, Precision Algorithms

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