Feedback on 13-253 Environmental Conditions log page

Gerry Houlder gerry.houlder at
Wed Apr 16 07:24:07 PDT 2014

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Ralph, I should have stated "one set of limits", not thresholds. You are
correct that log thresholds are not in play here and we should try harder
to avoid that confusion.
After thinking about the task of adding a separate set of limits for each
temperature and humidity parameter, it could be difficult to come up with
wording to describe which limit parameters are associated with which
temperature/ humidity parameter. A solution to this is to redefine the
grouping so that a temperature reading and the four parameters related to
that temperature reading are grouped into a single log parameter that is 20
bytes (4 byte header, 1 byte reserved, 1 byte temperature, 4 bytes critical
temp limits, 4 bytes operating temp limits, 2 bytes lifetime temp, 2 bytes
temp since power on, 2 bytes reserved to round to a 4 byte boundary). Is
this the direction to go with this?
On Tue, Apr 15, 2014 at 7:34 PM, Ralph Weber <Ralph.Weber at> wrote:
>  All of the log parameters defined in 13-253r3 are binary lists. Log
> thresholds do not apply to this kind of log parameter.
>  ------------------------------
> *From:* owner-t10 at [owner-t10 at] on behalf of Gerry Houlder [
> gerry.houlder at]
> *Sent:* Tuesday, April 15, 2014 2:30 PM
> *To:* T10 Reflector
> *Subject:* Re: Feedback on 13-253 Environmental Conditions log page
> On Tue, Apr 15, 2014 at 1:58 PM, Kevin D Butt <kdbutt at> wrote:
>> Gerry,
>> I have received some feedback related to the environment conditions log
>> page proposal
>> (1) Using the parameter code from 0000h to 000Fh, we can select a certain
>> temperature sensor from up to 15 temperature sensors. Using the parameter
>> code from 0020h to 002Fh, we can select a certain humidity sensor from up
>> to 15 humidity sensors. But there is no way to know which sensors are
>> valid/active or not.
>> I think it is useful for the user if we have another parameter code that
>> returns the valid/active temperature sensors.
> GH: The intent that only the number of sensors that are supported will be
> listed. For example, if only two temperature sensors are supported then
> only parameter 0000h and parameter 0001h will exist in LOG SENSE parameter
> list and there will not be any parameter numbers 0002h through 000Fh. This
> is why the support requirements say "at least one" or "optional". Anything
> listed as optional is not guaranteed to be implemented.
>> (2) The log page allows us to manage up to 15 sensors for both
>> temperature and humidity. Each of them can be attached to the different
>> location. For example, we can check the DRAM temperature and head
>> temperature independently.
>> But the Critical Temperature/Relative Humidity Limits, Operating
>> Temperature/Relative Humidity Limits, Lifetime Temperature/Relative
>> Humidity, and Temperature/Relative Humidity Since Power On has only one
>> entry. The criteria of these threshold must be different depending on the
>> target object. For example, DRAM might have tolerance to 80 degree Celsius
>> but the tape film might be melted. The hardware developer usually allocate
>> different criteria to each sensor(refer to
>> When I work with ThinkPad
>> development team, they have different threshold to each sensor). So these
>> entries should be assigned to each sensor independently.
> GH: discussion to date had indicated that one set of thresholds, applied
> to all of the sensors, was sufficient. i will consider this change if
> discussion at the next CAP meeting is in favor of the change.
>> This makes a lot of sense to me.  I suggest that a good solution would be
>> to add a parameter in Log Page 0Dh (i.e., existing Temperature log page)
>> that is a list of sensors supported.  Each subpage could be for a
>> sensor number (i.e., subpage 01h could be for temperature sensor #1 and
>> humidity sensor #1; subpage 02h could be for temperature sensor #2 and
>> humidity sensor #2).  Parameter 0000h of each subpage could be a validity
>> flag.
>> Alternately to putting the list of supported subpages in the Temperature
>> log page, subpage FFh could be used to provide the list of supported
>> subpages.
>> I know this is a major change, but I think it is a much better solution.
>> Thanks,
>> 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

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