Kurt Chan kc at
Thu May 4 11:44:38 PDT 1995

| For ensuring delivery of deferred errors, it would
| be just as good for the target to use the following procedure:
| 1) Send the FCP_RESP frame with the deferred error.
| 2) Log the defferred error (in this case, the loss of the cached data).
| If the FCP_RESP was lost, the initiator would discover it after a ULP
| timeout and it could then read the log to discover that the cached data was
| lost. Again, this procedure uses existing SCSI-3 procedures--no
| reinvention.


You're right about deferred errors - there are other methods to
determine if a deferred errors are reported, such as logs.  Would a
new proposal be needed to describe how to report deferred errors using
log pages?

| I do not think this is correct. ACA remains in effect until it is
| explicitly cleared by the initiator with a CLEAR ACA TM function.

Right again - the autosense only clears the ACA if NACA=0 in the CDB
of the faulting command.  After several months of reading SAM, I'm
still trying to understand ACA (am I just thick, or is this difficult

Then the only question I have with respect to SAM compliance is:

  "Sense data shall be preserved by the logical unit until it is
   transferred by one of the methods listed below or until another
   task from that initiator is entered into the task set.  The
   information may be obtained by the intiator through:

   a) The REQUEST SENSE command
   b) An asynchronous event report
   c) Autosense delivery"

I'd like to get a clearer definition of what SAM means (from the
Target's perspecive) by the term "transferred".  Does this imply
"successful transfer", or does merely refer to the act of physically
transmittingt the autosense?  

If it means successful transfer, then we may have to reevaluate
whether or not SPI conforms, and whether or not FCP without confirmed
responses conforms.  If it means just the physical transfer, then
both FCP and SPI conform to this clause.

Any SAM experts care to comment?

      Kurt Chan                          kc at
      Hewlett-Packard                    Voice: 916-785-5621
      System Interconnect Lab            Fax:   916-785-2875

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