Request to SBC, SBC-2 from Fuji

keiji_katata at keiji_katata at
Wed Dec 18 18:37:11 PST 2002

* From the T10 Reflector (t10 at, posted by:
* keiji_katata at

Thank you Elliott,

I forgot to write the most important question. I would like to check that
SPC-x, SBC-x already has the similar function or proposal like "Enhanced
Defect Reporting and EMCDR field", or not. As the result of my personal
survey, I can not find any. In MMC4 meeting, I also do not receive such
comment. If similar function has been defined already, MMC/Fuji people need
to examine to use the function, I think.

As far as I know, Mode Parameter page code and its contents can be device
type dependent. So I think MMC4 can have EMCDR field in MMC4 Read/Write
Error recovery mode page.
I'm not sure that Command Descriptor Block has same manner with Mode
Parameter. In case of Streaming bit in Read 12/Write 12 command, currently
it is MMC device specific bit definition. If this is allowed in SCSI
environment, I need not propose Streaming bit of Verify 10 to SBC, SBC-2.
Actually command description is device type specific now. For example Write
10/12 of MMC has restricted overwrite function. This is completely
different with the Write command in SBC, SBC2. Sequential (e.g. Tape)
device also has its specific definition.

In case of 16 bytes CDB length, ATAPI device can not use it now. Because 16
bytes CDB is defined newly, many software and hardware e.g. tailgate
interface can not accept it.

Anyway, I would like ask 2 questions to all T10 people.

1. Do SPC-x, SBC-x have similar function with "Enhanced Defect Reporting
and EMCDR field"?
2. Is it allowed that CDB has device type specific field?

I will be in MMC4 WG meeting room. If CAP people want to ask us (me) any
question, I would like to visit CAP meeting room. Let me know at the time.

Best regards,

Keiji Katata

from:  owner-t10 at

to:    <keiji_katata at>, <t10 at>
cc:    <mtfuji5 at>, <twg3 at>, "Greg Fry"
       <GFRY at>, "Lee Prewitt" <leep at>, "John
       Bertagnolli" <jbert at>, "Maki Yoshioka"
       <myoshioka at>, "Yoshiyuki Uchiyama"
       <uchiyama at>, "Maik Langenberg" <MLangenberg at>
subject:    RE: Request to SBC, SBC-2 from Fuji

* From the T10 Reflector (t10 at, posted by:
* "Elliott, Robert (Server Storage)" <Elliott at>

> -----Original Message-----
> From: keiji_katata at
> [mailto:keiji_katata at]
> Sent: Wednesday, December 18, 2002 1:40 AM
> To: t10 at
> Subject: Request to SBC, SBC-2 from Fuji
> ...
> -- Item 2 --
> MMC device supports streaming Read/Write by setting of streaming bit in
> Read 12, Write 12. Some members pointed out that device behavior of Read
> streaming=1 may be different with streaming=0. And to recover from fatal
> error quickly (for example fatal error due to finger print), I proposed
> another behavior when streaming bit is set to 1, for example short time
> length comparing with streaming=0.
> Ordinary Read operation will take 7 - 10 sec time length when device
> performed retry seek/read and was encountered fatal error. To find clear
> place beyond finger print, 7 - 10 sec time length is too long. Therefor
> use Verify command onto Real time packet, streaming bit is required.
> So we would like to ask Item 2 that allocate new streaming
> bit at Byte 6, bit 7 of VERIFY (10) Command.

Neither READ (12) nor WRITE (12) in SBC-2 have a "Streaming" bit today.
MMC-4's versions of those commands have that bit.

Does this belong in SBC-2's VERIFY (10) or is it best defined in
MMC-4's VERIFY (10)?

If SBC-2, does that mean its READ (12) and WRITE (12) commands need to
a Streaming bit?  How about VERIFY (12)?  How about READ (16), WRITE
and VERIFY (16)?

If MMC-4, should I mark that field as "Restricted" rather than
in SBC-2 so it doesn't get used for something else?

> I will attend the next MMC WG at Portland. So if you have comment or
> question, please visit MMC WG meeting. Also I welcome your comment via
> T10/Fuji reflector.
> Best regards,
> Keiji Katata

Rob Elliott, elliott at
Hewlett-Packard Industry Standard Server Storage Advanced Technology

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