[Nut-upsuser] Server not shutting down before power loss

Jonah Naylor jonahnaylor at gmail.com
Tue Dec 29 11:33:19 UTC 2015

HI thanks for replying and helping.

I've now ran the UPS down a few times from full charge to test and I don't
think it's the batteries or a problem with the UPS itself. I can watch it
go from 100% right down to 1% over 20 minutes etc and then the power gets
so low that everything just powers off!

I think it's down to Nut not actually shutting down my server that is my
problem... The battery on the UPS seems to hold plenty long enough from a
full charge, giving lots of time for a shutdown. How can I get the shutdown
to occur early, say when the battery is 50% to play it safe and just test
and make sure that nut is even sending a command to shutdown and why it
isn't happening?

You'll have to excuse me as I've not used nut before, but I'm sure it's an
Ubuntu or nut config problem here and that the shutdown sequence isn't
happening and not my UPS...

Thanks once again for any help to get this working. It would be fantastic
if it would just shutdown early on LOWBATT rather than waiting until the
very last minute and me not knowing it's going to make it or the shutdown
not evening happening!

On 29 December 2015 at 00:38, Julian H. Stacey <jhs at berklix.com> wrote:

> > Hi I hope someone can please help.
> >
> > I have an Ubuntu Server running 14.04.3 LTS and using an APC ES550 UPS
> > connected via USB.
> >
> > I've installed Nut and can see it does monitor the UPS correctly and give
> > the correct stats with battery percentage etc.
> >
> > But on doing a "real" test and unplugging the UPS from the power supply,
> > after watching the battery drop slowly suddenly the server just lost
> power
> > along with the UPS and monitor. No graceful shutdown and I didn't see any
> > attempt at a warning or shutdown in any way.
> >
> > Now I realise my UPS is no use at all if my system doesn't shutdown.
> >
> > Can anyone please help me get this to work as I'm vulnerable at present.
> Chuckle. I remember a previous New Year I said "Watch This" pulled the
> plug,
> & what visitors expected & I did Not ... Happened ... All disc spun down.
> Demo effect ! I hadnt checked batteries for a while.
> As ever, as I & others have commented over years in archives,
> first disconnect batteries & check voltage of each battery, - dead easy,
> Then much more important: calculate internal resistance of each battery.
> Batteries go bad after some years, even on trickle charge.
> Measure voltage drop when driving a load such as 1 or a few car
> headlamp bulbs in parallel. Then its simply Ohms law V=IR,
> If voltage drops from say 13V to 11V & if you use 1 headlamp that
> uses maybe 4 amps, then 13-11 / 4 = 2/4 = 0.5 which is on high side,
> you dont want higher, better 0.3 or less.
> Your UPS for PC's will prob. want a lot more than 4 amps, so low
> internal resistance is critical to good UPS performance.
> If you decide to use computer as your measurement load instead or
> a car headlamp bulb, remember the static inverter is still On,
> generating 110 or 240 Volts, dont kill yourself or blow stuff up
> while measuring :-)
> > Nut Version: 2.7.1-1ubuntu1
> > Nut installation method was just through apt from standard Ubuntu repos.
> >
> > Thanks very much indeed.
> >
> Cheers,
> Julian
> --
> Julian Stacey,  BSD Linux Unix Sys. Eng. Consultant Munich
> http://berklix.com
>  Reply After previous text to preserve context, as in a play script.
>  Indent previous text with >            Insert new lines before 80 chars.
>  Use plain text, Not quoted-printable, Not HTML, Not base64, Not MS.doc.
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