Saveable mode pages

Ralph Weber Ralph.Weber at
Thu Feb 12 05:13:32 PST 2015

Attachment #1: <a href="">nameless-3200-2-1.html</a>

If there is a decent consensus that adding some "(see ...)" text resolves the
original issue, I have no problem incorporating that in SPC-5 r04 as an
editorial change.
If the headaches are bigger and a cleanup proposal is needed, then I would
rather have the addition on record in an approved proposal.
All the best,
From: owner-t10 at [owner-t10 at] on behalf of Gerry Houlder
[gerry.houlder at]
Sent: Wednesday, February 11, 2015 8:36 PM
To: Kevin D Butt
Cc: Curtis Ballard; Paul Stone (Paul.Stone at; Dennis Appleyard;
T10 org
Subject: Re: Saveable mode pages
It is interesting that SPC-4 promises behavior of FORMAT UNIT command when
FORMAT UNIT command is not included in SPC-4 and there isn't even a "see
command standard" reference. I think you would be happier with a statement
like "Saveable mode pages may also be saved by a FORMAT UNIT command (see
SBC-4 and SSC-x)". i guess we missed this during letter ballot review last
On Wed, Feb 11, 2015 at 4:02 PM, Kevin D Butt
<kdbutt at> wrote:
I am confused by 6.12.5 Saved values
<<All saveable mode pages should be considered saved if a MODE SELECT command
issued with the SP bit set to one has completed with a GOOD status or after
the successful completion of a FORMAT UNIT command.>>
This states that after the successful completion of a FORMAT UNIT command ALL
saveable mode pages should be considered saved. This may be good for block
devices, but why are tape devices included in this? On tape devices a FORMAT
UNIT command formats the tape but does not change other things in the device
- nor do we want it to.  Also, I can interpret this to say, when doing a
FORMAT UNIT command part of the processing is to take all the Current values
of mode pages that are saveable and save them. This may violate the intent of
the application client which explicitly did not set the SP bit in the MODE
SELECT that updated the Current values (and explicitly did not update them to
Saved values).
Is anybody else bothered by this?
Kevin D. Butt
SCSI Architect, Tape Firmware, CAMSS
T10 Standards
MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
Tel: 520-799-5280<tel:520-799-5280>
Fax: 520-799-2723<tel:520-799-2723> (T/L:321)
Email address: kdbutt at

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