Receive Copy Results list identifier

Joseph C. Nemeth jnemeth at palg.com
Thu May 1 14:23:24 PDT 2003


* From the T10 Reflector (t10 at t10.org), posted by:
* "Joseph C. Nemeth" <jnemeth at palg.com>
*
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In SPC-3r12, the RECEIVE COPY RESULTS text describing the List
Identifier states:


If no EXTENDED COPY command known to the copy manager has a matching
list identifier, then the command shall be terminated with a CHECK
CONDITION status...




Isn't service action 03h (OPERATING PARAMETERS) typically used prior to
initiating any EXTENDED COPY command, to determine operating parameters
for the EXTENDED COPY command? In which case, there would be no matching
EXTENDED COPY list identifier, and the operating parameters could never
be determined.

This statement above therefore implies that an EXTENDED COPY command
would have to be executed first to establish a list identifier, followed
by a RECEIVE COPY RESULTS with that list identifier and a service action
of OPERATING PARAMETERS. Since the operating parameters are not known to
the initiator prior to executing this service action, the first EXTENDED
COPY command must generally be a dummy command, used purely to establish
a list identifier so that operating parameters can be determined.

In SPC-2r20, a dummy EXTENDED COPY command made some sense, as a
brute-force method to determine if EXTENDED COPY is supported by the
target. In SPC-3r12, the 3PC bit in the Standard Inquiry provides this
information, so there is no longer any justification for sending a dummy
EXTENDED COPY command - other than to establish a list identifier to
make RECEIVE COPY RESULTS work.

This seems very inelegant to me.

Can RECEIVE COPY RESULTS be relaxed so that a service parameter of
OPERATING PARAMETERS does not require a prior list identifier, or will
this stand as written?



Joseph C. Nemeth          Precision Algorithms          (970) 226-5427



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In SPC-3r12, the RECEIVE COPY RESULTS text describing the List Identifier states:
 If no EXTENDED COPY command known to the copy manager has a matching list identifier, then the command shall be terminated with a CHECK CONDITION status...
 
Isn't service action 03h (OPERATING PARAMETERS) typically used prior to initiating any EXTENDED COPY command, to determine operating parameters for the EXTENDED COPY command? In which case, there would be no matching EXTENDED COPY list identifier, and the operating parameters could never be determined.
 
This statement above therefore implies that an EXTENDED COPY command would have to be executed first to establish a list identifier, followed by a RECEIVE COPY RESULTS with that list identifier and a service action of OPERATING PARAMETERS. Since the operating parameters are not known to the initiator prior to executing this service action, the first EXTENDED COPY command must generally be a dummy command, used purely to establish a list identifier so that operating parameters can be determined.
 
In SPC-2r20, a dummy EXTENDED COPY command made some sense, as a brute-force method to determine if EXTENDED COPY is supported by the target. In SPC-3r12, the 3PC bit in the Standard Inquiry provides this information, so there is no longer any justification for sending a dummy EXTENDED COPY command - other than to establish a list identifier to make RECEIVE COPY RESULTS work.
 
This seems very inelegant to me.
 
Can RECEIVE COPY RESULTS be relaxed so that a service parameter of OPERATING PARAMETERS does not require a prior list identifier, or will this stand as written?
 
Joseph C. Nemeth          Precision Algorithms          (970) 226-5427
 

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