Ubuntu 20.04.3 desktop (Cinnamon) - SSH disconnects when user logs off the desktop!

[Bo Berglund]

On Sat, 22 Jan 2022 18:23:06 +0100, Bo Berglund <bo.berglund at gmail.com> wrote:

>I have spent many hours today trying in vain to fix this problem. And it *HAS*
>to be fixed before I deploy the computer to my summer cottage, where we just got
>fiber installed so I can place a server like this and still have access to it
>from home. But it will rely on a person NEVER having to handle the device
>physically!
>

Update:
-------
As part of my efforts I have also added a reporting utility I usually place on
every Raspberry Pi I configure in order for it to report its IP address so I can
connect via SSH.
I add a call to the reporting utility to crontab and specify that it should run
on boot:

@reboot /home/bosse/bin/ipreport.sh 60 > /dev/null 2>&1

And lo and behold, it turns out that my Ubuntu system reboots regularly at 6
minute interval!

Between 15:07 and 17:45 when I was watching sport on TV I received 24 such
report messages at 6 min intervals!

The utility also logs the time of every invocation so I know exactly when the
reboots happened.

So now I need to figure out what is causing the reboots that occur at this
regularity!

How can that be done?
Is there some kind of error log or boot log one can look at?
syslog itself seems to be insurmountably big...

I tried to find a reboot at the logged time in syslog but it turns out that in
the same second as a call to the reporting utility was done there is more than
1365 lines of logging....

I also tried to get the filtering done by grep but failed...

syslog.bosse is a copy of syslog I made in order to be able to work with it.

I created this using this command to get a text file:

cat syslog > $HOME/syslog.bosse

Then I tried grep but it failed:

$ grep -F "Jan 22 15:24:40" syslog.bosse
Binary file syslog.bosse matches

I have no idea why this happens to grep, so I have trouble navigating the log.
The timestamp is on every log line so why can't grep find them?

Any ideas welcome!


-- 
Bo Berglund
Developer in Sweden