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

[Bo Berglund]

On Sun, 23 Jan 2022 23:40:19 +0100, Bo Berglund <bo.berglund at gmail.com> wrote:

>So tonight I made a final attempt at installing linuxmint-20.3-cinnamon-64bit
>and it too is rebooting, in this case 11 minutes after I logged out from the
>desktop to the login screen... :(
>
>I have now reached the next reboot so I can time the cycle: 673 s this time.
>I will let it run like this for an hour or so and then inspect the log the
>reporter creates to get a handle on the repeatability.

It *was* repeating at approximately 670 s interval when staying on the login
page!

>Can I modify the startup somehow to make it automatically log me in to the
>desktop when it boots? Then it would never stay on the login screen and the
>reboots might not happen...
>It is available during install, but can it be done later too?

Yes, I found the way to make the system log me on to the GUI automatically on
reboot:
https://linuxhint.com/enable-auto-login-on-boot-linux-mint/

With this in place I have rebooted and it did log me in to the desktop
automatically.

And it does *not* reboot anymore.
So the system is running for many hours (overnight) without further reboots.

I can thus use it in this way like I intended as a standalone system on a remote
location which will mainly be accessed using SSH but occationally via VNC to the
desktop.

Of course VNC will use a different desktop since it is virtual.

A final test for today is to make sure that the system also runs *without* a
monitor attached so I will shut down and disconnect the monitor and then power
on again and see what gives.

But I will install TigerVNC first of course.

Later:
------
Another snag here!
If I disconnect the physical monitor after I have installed and successfully
tested TigerVNC on display :1, then it will *not* boot and since I have no
display attached I cannot say how far it gets. In any case it never comes
on-line on the LAN.

Strangely if I leave the monitor cable in place but power down the monitor in
the other end of the cable, then it boots and I can use VNC! What is the
difference? Monitor disconnected or a powered down monitor in the other end of
the cable?

The monitor connection is by way of DiaplayPort, the HP PC has 2 of these and
nothing else...

So as it is now I cannot use it after all, since there will be no monitor
attached in the end location. The plan was to have the PC stored in a cupboard
somewhere and accessed via SSH and VNC. But of course that does not work if it
behaves in this way.

I have a dozen or so Raspberry Pi units which run a Debian variant of Linux.
These will not behave like this, they boot reliably and if there is no monitor
attached they still do. And I access them all via VNC just fine.
I could never believe that Linux on PC hardware would behave like this...


-- 
Bo Berglund
Developer in Sweden