Letter ballot comments on THRESHOLD EXPONENT field (fixed)

Gerry Houlder gerry.houlder at seagate.com
Thu Aug 22 13:37:40 PDT 2013


Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r1308224_f.htm">HTML-formatted message</a>

The new proposed wording isn't quite right. i suggest the following:
(a) delete the sentence "A threshold exponent field indicates the threshold
set size." It doesn't directly indicate the threshold set size, it is only
a component of the equation that defines the threshold set size.
(b) Add the threshold set size definition as another equation after the
"... such that:"
threshold set size	   number of LBAs indicated by 2**(threshold
exponent)
This change also helps reinforce the fact that the threshold set size is
only defined if the threshold exponent is a non-zero value, because the
first sentence of the paragraph requires the threshold exponent to be
non-zero.
On Thu, Aug 22, 2013 at 3:01 PM, Penokie, George
<George.Penokie at lsi.com>wrote:
> Ignore the first note.
>
> ** **
>
> OK, so Fred thinks this wording would work.****
>
> ** **
>
> A threshold exponent field indicates the threshold set size. A threshold
> exponent field set to zero indicates that the logical unit does not support
> logical block provisioning thresholds.****
>
> If logical block provisioning thresholds are supported, then the threshold
> exponent shall be a non-zero value selected such that:****
>
> …..****
>
> ** **
>
> Bye for now,****
>
> George Penokie****
>
> ** **
>
> LSI Corporation****
>
> 3033 41 St NW****
>
> Rochester , MN 55901****
>
> ** **
>
> 507-328-9017****
>
> george.penokie at lsi.com****
>
> ** **
>
> *From:* Knight, Frederick
[mailto:Frederick.Knight at netapp.com<Frederick.Knight at netapp.com>]
>
> *Sent:* Wednesday, August 21, 2013 11:43 AM
> *To:* Kevin D Butt; Roger Hathorn; Penokie, George; T10 Reflector
> *Subject:* RE: Letter ballot comments on THRESHOLD EXPONENT field****
>
> ** **
>
> Yup, Kevin is correct.  We shouldn’t really invert this because of the LOG
> page use of this field.****
>
> ** **
>
>		  Fred****
>
> ** **
>
> *From:* owner-t10 at t10.org [mailto:owner-t10 at t10.org <owner-t10 at t10.org>]
*On
> Behalf Of *Kevin D Butt
> *Sent:* Tuesday, August 20, 2013 1:21 PM
> *To:* Roger Hathorn; George.Penokie at lsi.com; T10 Reflector
> *Subject:* Fw: Letter ballot comments on THRESHOLD EXPONENT field****
>
> ** **
>
> IBM does not accept this revision to SBC-3.  See below for the reasoning.
>
> Kevin D. Butt
> SCSI Architect, Tape Firmware, T10 Standards
> Data Protection & Retention
> MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
> Tel: 520-799-5280
> Fax: 520-799-2723 (T/L:321)
> Email address: kdbutt at us.ibm.com
> http://www-03.ibm.com/servers/storage/
> ----- Forwarded by Kevin D Butt/Tucson/IBM on 08/20/2013 10:19 AM -----
>
> From:        Roger Hathorn/Tucson/IBM
> To:	     Kevin D Butt/Tucson/IBM at IBMUS,
> Date:        08/19/2013 06:20 PM
> Subject:	  Re: Fw: Letter ballot comments on THRESHOLD EXPONENT field
> ****
> ------------------------------
>
>
>
> Kevin,
> I completely disagree with this statement:
> "A threshold exponent field set to a non-zero value indicates the logical
> unit supports logical block provisioning thresholds (see 4.7.3.8)."
> That is a change to the current definition and adds a normative
> requirement that  if I support resource counts in the LBP log page, then
> I shall also	support logical block provisioning thresholds, which also
> states that I have to support the logical block provisioning mode page.
>
> I am OK with saying "A threshold exponent field set to zero indicates that
> the logical unit does not support logical block provisioning thresholds.",
> because that is already in the draft.    I am not OK with the inverse.
>
> This is the main reason for my comment that was rejected:
> The threshold exponent is also used for expressing available and used
> resource counts in the LBP log page.	One could support providing of the
> log page resource counts without supporting LBP thresholds.
> The response was:
> "No change - The one usage of threshold exponent in the LBP log page
> references back to this VPD page and now has modified wording to make the
> i.e, clearer (see SBC-3 revision 35f or later). The threshold exponent
> referenced in the LBP log page is also the same threshold exponent defined
> in the VPD page. *If the contents of the THRESHOLD EXPONENT field are
> non-zero then the device supports these thresholds. It is not just implied
> it is stated as such in the text."*
>
> The content of the LPB log page does not contain thresholds, it contains
> resource counts. They are useable without supporting thresholds.  I don't
> see where it is stated anywhere in the letter ballot version of the text.
>
> Feel free to forward this response.
>
> Roger G. Hathorn
> STSM, Storage Systems Development
> IBM Systems and Technology Group
> Tel: 520-799-5950 (T/L: 321-5950)****
>



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