insane fan speed readings from lm_sensors

[Leon Goldstein]

Lonni:  beats me.  All i can recommend is to get a line voltage monitor 
and see what is going on.

The UPS should stop surges, but may not have any effect on a gradual 
voltage increase that remains below its threshold.

On 9/12/19 8:54 PM, Lonni J Friedman wrote:
> Except that I've got a UPS that is definitely shielding me from such
> voltage spikes.  Also, this oscillation happens for nearly 6 hours
> every day.  Its not a one time event.
>
> On Thu, Sep 12, 2019 at 5:53 PM Leon Goldstein <metapsych at earthlink.net> wrote:
>> Lonni: the fact that this phenomenon is observed at the same time of day
>> makes me think your electric utility is the cause. Possibly another
>> power plant is coming on line to meet expected power demands at that
>> time and is causing voltage spikes.
>>
>> On 9/12/19 8:48 PM, Lonni J Friedman wrote:
>>> I'm using collectd's sensor plugin, which is calling out to
>>> libsensors.so.4 (which is part of lm_sensors).
>>>
>>> I'm using a UPS, which definitely is doing its job, as I have
>>> semi-frequent power issues, and the UPS has shielded everything from
>>> them.
>>>
>>> I'd be inclined to agree that there's a hardware problem, however the
>>> fact that this weird problem consistently happens during the same 6
>>> hour span every time makes me think something else is causing this
>>> behavior.
>>>
>>> On Thu, Sep 12, 2019 at 5:44 PM Leon Goldstein <metapsych at earthlink.net> wrote:
>>>> Lonni:  what app are you using to report the fan RPM's?
>>>>
>>>> Is the fan actually running faster when the app reports that it is
>>>> speeding up?  I also presume you are using a good UPS with voltage
>>>> stabilization?  I have a voltage monitor plugged into a wall socket, and
>>>> observe that the voltage can fluctuate a bit during the day,
>>>> particularly during the hottest time of the day when air conditioners
>>>> are in heavy use.  That, and the fact that hot power transmission lines
>>>> have more resistance.
>>>>
>>>> Assuming your case fan is tapping off of a socket on the mobo, there may
>>>> be a voltage excursion.  It might be a good time to replace your power
>>>> supply.
>>>>
>>>> On 9/12/19 8:00 PM, Lonni J Friedman wrote:
>>>>> This isn't the CPU fan, its the chassis case fan. I'm already
>>>>> capturing CPU activity, and its basically idle the entire time.  Keep
>>>>> in mind, this starts happens in the early morning hours (4AM), when
>>>>> the system isn't being actively used.  The exhaust fan on this system
>>>>> is whisper quiet, even when running at nearly 1400RPM.
>>>>>
>>>>> On Thu, Sep 12, 2019 at 9:21 AM Leon Goldstein via Linux-users
>>>>> <linux-users at linux-sxs.org> wrote:
>>>>>> Hi Lonni:
>>>>>>
>>>>>> All I can suggest is run System Monitor to see the CPU % activity when
>>>>>> the fan speed rises.
>>>>>>
>>>>>> Can you hear the difference in fan speed?  I have a laptop that gets
>>>>>> very conspicuously noisier when CPU capacity is peaking, as e.g. during
>>>>>> an update kernel installation.  (I'm using Mint 18.3 Mate.)
>>>>>>
>>>>>> On 9/11/19 8:39 PM, Lonni J Friedman via Linux-users wrote:
>>>>>>> Since its so quiet here (when is it not?), I'll drop a puzzle on you
>>>>>>> fine folks to noodle on.
>>>>>>>
>>>>>>> I recently started monitoring my system exhaust fan speed (RPMs),
>>>>>>> mostly out of curiosity.  What I discovered has exposed a mystery that
>>>>>>> I'm struggling to explain.  Every day between 04:00 & 10:00, the fan
>>>>>>> speed readings start to rapidly oscillate between sane numbers (under
>>>>>>> 3000 RPM) and insane numbers (over 10,000 RPM).  For the rest of the
>>>>>>> day, the readings are perfectly normal & reasonable.  Its always
>>>>>>> during that same time window.  There's no way this exhaust fan is even
>>>>>>> capable of spinning at the rate that is being reported.  This has to
>>>>>>> be an erroneous reading.
>>>>>>>
>>>>>>> Here's a graph of what I'm talking about:
>>>>>>> https://imgur.com/erXGz4J
>>>>>>>
>>>>>>> There's nothing in dmesg or /var/log/messages to explain this
>>>>>>> behavior.  I've looked at every cronjob running on the system for some
>>>>>>> bizarre correlation, and can't find anything.
>>>>>>>
>>>>>>> I'd like to think that if this was a flaky sensor, it wouldn't be so
>>>>>>> reliable in when it happens.  So something else must explain the
>>>>>>> weirdness.  Anyone have ideas/suggestions?
>>>>>>> _______________________________________________
>>>>>>> Linux-users mailing list
>>>>>>> Linux-users at linux-sxs.org
>>>>>>> http://mailman.celestial.com/mailman/listinfo/linux-users
>>>>>>>
>>>>>> --
>>>>>> Leon A. Goldstein
>>>>>> System L3
>>>>>> Linux Mint 17.3
>>>>>>
>>>>>> _______________________________________________
>>>>>> Linux-users mailing list
>>>>>> Linux-users at linux-sxs.org
>>>>>> http://mailman.celestial.com/mailman/listinfo/linux-users
>>>> --
>>>> Leon A. Goldstein
>>>>
>>>> Compulab System
>>>> Linux Mint 18.3
>>>>
>> --
>> Leon A. Goldstein
>>
>> Compulab System
>> Linux Mint 18.3
>>
-- 
Leon A. Goldstein

Compulab System
Linux Mint 18.3