insane fan speed readings from lm_sensors

[Lonni J Friedman]

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
>