Format Unit SI bit

Gerry Houlder gerry.houlder at seagate.com
Tue Jun 7 08:17:46 PDT 2011


Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r1106070_f.htm">HTML-formatted message</a>

I think Mark's interpretation is too broad. The SI bit is intended to
trigger a vendor specific security initialize feature. Things the device has
to do to implement this take precedence over other bits that might specify
conflicting demands. However things that specify the required final format
(e.g., logical block size, FMTPINFO) and whether existing defect lists are
included or not (e.g., FMTDATA, CMPLST, DEFECT LIST FORMAT, defect list
length) should still be obeyed. If an initialization pattern is specified,
that should be the pattern left on the media after the security initialize
is complete. The SI bit probably affects how defective areas (i.e., areas
excluded from the user data area) are treated, but should not cause the
device to ignore instructions about which areas are to be handled as
defective areas.
On Fri, Jun 3, 2011 at 10:56 AM, Mark Evans <Mark.Evans at wdc.com> wrote:
>  Hi Truong,
>
>
>
> The SI bit was added into the INITIALIZATION PATTERN DESCRIPTOR for the
> FORMAT UNIT command in SBCr-05 based on proposal 96-186R1.  As you wrote
the
> definition of the bit was modified slightly in SBC-r06 as the result of
> discussion at the SCSI working group meetings in October of 1996.  The
> definition of the SI bit has not been changed since that time.
>
>
>
> What I think we really intended the new wording to mean is, “If the SI bit
> its set to one, then the device server shall ignore:
>
>
>
> a)	   the FMTPINFO field;
>
> b)	  the FMTDATA bit;
>
> c)	   the CMPLST bit;
>
> d)	  the DEFECT LIST FORMAT field;
>
> e)	   all of the bits and fields in the parameter list header, except
> the IMMED bit; and
>
> f)	    any defect list data.
>
>
>
> Others may correct me if I’m wrong.  You know who you are, and I’m sure you
> will – ha!
>
>
>
> Please feel free to call or send an email to me with any comments or
> questions that you have about this stuff.
>
>
>
> Regards,
>
>
>
> Mark Evans
> Western Digital Corporation
> 5863 Rue Ferrari
> San Jose, CA 95138
> Email: mark.evans at wdc.com
>
>   ------------------------------
>
> *From:* owner-t10 at t10.org [mailto:owner-t10 at t10.org] *On Behalf Of *Truong
> Nguyen - SISA
> *Sent:* Thursday, June 02, 2011 5:54 PM
> *To:* t10 at t10.org
> *Subject:* Format Unit SI bit
>
>
>
> In SBC3r27, in the Format Unit initialization pattern descriptor subclause
> 5.3.2.3, there is a statement regarding the SI bit precedence:
>
>
>
> "An SI bit set to one shall take precedence over any other FORMAT UNIT CDB
> field."
>
>
>
> What is this statement supposed to mean specifically?
>
>
>
> It seems as though the statement was added some time ago in SBCr6:
>
>
>
> ftp://ftp.t10.org/t10/t10r/1996/r9610141.htm
>
>
>
> "Clarified SI by adding the statement An SI bit set to one shall take
> precedence over any other FORMAT UNIT field."
>
>
>
> I could not find any proposals associated with the modification.
>
>
>
>
>
> Thanks,
>
>
>
> Truong Nguyen
>
>
>
> Samsung Information Systems America
>



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