SSC-2: Discussion of Merits for another Letter Ballot

David Peterson (dap) dap at
Tue Nov 12 07:51:29 PST 2002

* From the T10 Reflector (t10 at, posted by:
* "David Peterson \(dap\)" <dap at>

Comments inline...dap

-----Original Message-----
From: Kevin D Butt [mailto:kdbutt at] 
Sent: Monday, November 11, 2002 4:12 PM
To: t10 at
Cc: Erich Oetting; Joe Breher; Michael Banther; Paul Suhler; Paul
Entzel; Tuong Vu; Dave Peterson
Subject: SSC-2: Discussion of Merits for another Letter Ballot

SSC-2 Working Group,

You all know that I have been advocating for another letter ballot for
SSC-2.  I am aware that there is a desire to complete the work and move
on to other activities.  I certainly agree that it would be nice to put
this thing to rest and move on, but I am uneasy about doing this.
Perhaps the issue is that I have not gone through this process before
and I am expecting too much.

As I understand the process, once we resolve the Letter Ballot comments,
we forward the document to INCITS.  INCITS then sends the document out
for public review and INCITS companies have an opportunity to comment.
If any NO votes are received, the document is sent back to T10 for
resolution.  If any public review comments were made, T10 will forward
the resolutions and any document changes to INCITS again.  Another
public review will be held. When public review is done, it goes through
some formalities and becomes a completed standard.

This leads me to believe that if there are problems with the standard
that we want addressed the best place to do it is before we forward it

I would like to discuss the issues with SSC-2 that are bothering me, and
see if I can be convinced that we do not need another letter ballot.
Perhaps an SSC-3 can sufficiently respond to the issues I currently

1.  Our resolution discussions have not been shared with the reflector
(our correspondence has only been between 8 companies, the eighth
company added only recently).  Only our responses to actual letter
ballot comments have been made available to the community at large. 

dap: Other than a few questions directed to the people involved in the
SSC-2 letter ballot comment resolution process prior to the last meeting
I can't recall any pertinent discussions not being discussed on the
reflector (e.g., obsoletion of some functionality). Anyways I don't
believe I'm obliged to share every letter ballot comment resolution
discussion with the reflector. And even if I did share every letter
ballot comment resolution discussion with the reflector that doesn't
mean the proper people are subscribed to the reflector. Also some people
have a tendency to read reflector email at their leisure. I could go

2.  We have changed the Explicit Address State Machine to the extent
that we have removed an entire state - while I agree this simplifies
things, it seems to be a significant and substantive change. 

dap: I fail to see your point. The removal of the explicit address mode
read capable state was done prior to entering letter ballot on SSC-2 rev
07. If you have/had a problem with the removal of this state a letter
ballot comment should have been made. And actually I believe you were
the one asking for it to be removed at one of the working group

3.  We have changed the entire document by replacing Logical Block
Address with Logical Object Identifier. - While this appears on the
surface to be an editorial change intended for clarification, it has
touched large portions of the document.  Has the intent of the previous
text been inadvertently changed?  (Logical Block having a different
meaning than the 'Logical Block' in Logical Block Address) 

dap: Yes, document terminology regarding "blocks", "logical block
address", has changed due to letter ballot comments. This has forced a
thorough review of all instances of the changed and related terminology.
As a result the document is much clearer and now actually has a chance
to reflect the desired intent. And yes, we do need to ensure it does
reflect the desired intent. Rev 08f will be available shortly for your

4.  We are trying to clarify the INFORMATION field and what it reports
on non-WRITE commands that fail for deferred errors.  This will
certainly effect a wide audience.  I do not believe that all the
different manufactures have implemented this the same way.

dap: This is one of the main reasons, if not the main reason, for a
standard and the letter ballot process (i.e., interoperability). This
comment is still unresolved pending input from the SSC-2 letter ballot
resolution participants. Are you saying this cannot be resolved without
another letter ballot? 


Kevin D. Butt
Fibre Channel & SCSI Architect
IBM Tape Microcode,
6TYA, 9000 S. Rita Rd., Tucson, AZ  85744
Tie-line 321; Office: 520-799-5280, Lab: 799-2869, Fax: 799-4138, Email:
kdbutt at

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