[Nut-upsuser] nut on armhf, r-pi4b IOW

Gene Heskett gheskett at shentel.net
Tue Jan 14 04:44:00 GMT 2020

On Monday 13 January 2020 22:31:55 Charles Lepple wrote:

> On Jan 12, 2020, at 12:58 PM, Gene Heskett wrote:
> > But this doesn't pass the smell test, 3 other machines that are
> > trained to reboot when power returns and have no ups fitted, were
> > NOT rebooted as evidenced by their reported uptimes, one of which
> > shows a 144 day uptime.  So why should this have been logged via a
> > -wall bc to every login it is servicing?
> >
> > There was no power failure IOW.
> The thing is that many UPS models will report "on battery" when the
> voltage fluctuates out of range, but a switching power supply might
> still be able to coast through it-- especially if the supply is
> oversized for the load at the time of the abnormality.

Oversized is hereby nominated for understatement of the week, if not 
longer.  Before I inserted the ups, flipping the power switch took all 
of 10 seconds to kill the red led on the pi4. So at a 5 amp rating, I'd 
say it was a wee tiny bit oversized.

Now I'd expect days if the battery is somewhere near fresh. :-)

> Since both "outages" (really, the on-battery states) were exactly 10
> seconds long means that the UPS was probably trying to "debounce" the
> voltage fluctuation by not switching back to line power immediately
> after the voltage went back to normal.

Well. since the weather was heavily wet and slightly "noisy" at the time, 
a couple nearby strikes might have bumped it I suppose, but a semi-stock 
old dell wasn't disturbed, and 2 intel shoeboxes with D-525-MW mobo's 
also survived whatever it was.  They are subject to wall power 
floobydust.  Wall power has improved some since several have installed 
standy's. I doubt if that's a co-inky-dance since those easily visible 
ones are an embarrassment to the power peddlers.

> For APCs and MGEs, I think it is typically 5 seconds.
> Several people have rigged up longer timers with upssched to not send
> the wall message until it has been on battery for, say, a full minute.

I'd still like an interpretation of that log, I stopped it when it was 
obviously looping at about 2 second intervals.

Cheers, Gene Heskett
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Genes Web page <http://geneslinuxbox.net:6309/gene>

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