reading blocks prior to a medium error

Douglas Gilbert dgilbert at
Tue Dec 28 08:16:39 PST 2010

* From the T10 Reflector (t10 at, posted by:
* Douglas Gilbert <dgilbert at>
George Penokie wrote:
 > This whole issue is about UNRECOVERED read errors
 > not RECOVERED read errors. All the read data is
 > valid when there is a RECOVERED read error. The
 > wording in SAM that states " While some valid data
 > may be present for other values of status, the
 > application client should rely on additional
 > information from the logical unit (e.g., sense data)
 > to determine the state of the buffer contents." allows
 > this.
I am now taking issue with the two adjoining sentences in
SAM-5 section 5.1 describing the Data-in buffer. In this
thread they have now be used (when the status is
   a) justify that in the case of blocks prior to a
      medium error (i.e. an unrecovered error) that
      the initiator "_shall_ treat the buffer contents
      as invalid";
   b) and when the sense key is recovered error, the same
      data-in buffer is valid because the following
      sentence contains some weasel words.
Since sense data is defined in SPC-4, would it not be better
that SAM-5 said nothing on the issue of validity of the
data-in buffer? Alternatively it could just say it was
valid when the status was good or condition met and refer
to SPC-4 for other cases.
IMO George Penokie's issue on this subject, raised at a
recent T10 meeting, is not resolved by reference to that
data-in buffer description in SAM-5.
Douglas Gilbert
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