Nut upsuser - Feb 2020 - UPS shuts down after restart

>> But I noticed two other details:
>> 1. I was a bit wrong with step 7 and 8 - Looks like the UPS is "OL
CHRG" (according to display) at first but goes to battery ("OL
DISCHRG" according to nut) right when the RasPi (and nut) is booting.
>> 2. When I pull the plug of the RasPi after UPS went down before main
power comes back (so between step 5 and 6), the UPS comes up in state "OL
CHRG" and is stable.
>>
>> Maybe nut is sending `upsdrvctl shutdown` right after boot again but
without shutting down the system or sending an notification? Is there a way to
check this reliably?
>
> indeed if the battery is discharged and in the same time nut sees "OL
DISCHRG",
> nut might trigger a shutdown (although, as far as I know,
> this should happen only for "OB DISCHRG").
Do you mean "fully discharged" (that is not the case here, not even
LB).
But I guess even in this case nut should trigger a clean system shutdown and not
only shutting down the UPS?

> I'd like to understand _why_ does the DISCHRG flag appear when the UPS
is actually online and
> charging. this could be a firmware error (the UPS sends incorrect data)
> or nut incorrectly reading ( or interpreting ) the data it receives.
I think nut is correctly reading the "OL DISCHRG" from the UPS. It is
obviously OL (I plugged it into the socket) and the display shows it's using
the battery.
My guess is, that nut is sending the shutdown to the UPS when booting up during
this scenario.
When I'm back at home, I'll try to manually call `upsdrvctl shutdown` to
check if the UPS then goes to 'OL DISCHRG' and try to capture an usbhid
dump. But I probably have only one minute time :-)

I hope I won't trash the SD card of the RasPi with all this crashing :-D

  Stefan

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> I'll try to manually call `upsdrvctl shutdown` to check if the UPS then
goes to 'OL DISCHRG'
I now tested the manuall `upsdrvctl shutdown` and the UPS goes to 'OL
DISCHRG'. So I think nut is sending the shutdown command to the UPS during
boot without setting FSD.

Just a wild guess: I recognized the system time in syslog during the
bootsequence is suspicious. It looks like there is too less time between the
shutdown logs and the boot logs. I think it's because the RasPi doesn't
have an RTC battery. Maybe there is some code somewhere in the nut startup,
which checks the timestamp of the POWERDOWNFLAG-file and the actual system time?


Stefan

Hi all,
> I now tested the manuall `upsdrvctl shutdown` and the UPS goes to 'OL
DISCHRG'.
> So I think nut is sending the shutdown command to the UPS during boot
without setting FSD.
I already attached "-DD" to the systemd-unit for upsmon (startup log
attached) to track this down. Sadly it looks ok - "OL DISCHRG" right
from the beginning. No traces of sending an shutdown.
I assume, if somebody sending an shutdown there must be something in the driver
debug output? I already tried to add "-DD" to the nut-driver
systemd-unit but only got that messge "This is not the driver you're
interested in" (btw: great message, thanks for this :-).

Can you give me some advice how to attach a "-DDD" to the usbhid-ups
right at the system start?

  Stefan