If this works as you reported then for me the error is ssd related.
If it was mine i would
Format the ssd, getting rid of partitions
Install lmde 5 that works
Test it
If thats fine
Try lmde6
Tests that
But easy option scrap ssd and stay with hard disk !
Révolution !
Of course not. This has to be possible as user.
Yes, before the Debian/LMDE people switched to systemd. But I don’t remember any details.
Done. The boot partition is now the first one; swap is at the end. Doesn’t work either.
You are mastering the art of negaative results
Strace only tracks things while linux is in control.
We need some way of logging what the BIOS is doing
What does reboot -f do?
Just the same, I assume, but requires root. and:
In most cases, filesystems are not properly unmounted before shutdown.
https://unix.stackexchange.com/questions/547008/how-reboot-process-works-in-linux
Yes reboot -f is not and elegant method. About equivalent to a power failure. I thought it might show if any of the preli inary steps were interfering.
It seems a modern reboot is different to an old fashioned soft boot or warm boot.
It does everything shutdown does, except the power off.
That does not leave much room for your bug
So what does power off do to the bios , that reboot does not do?
“A complete power off can clear some BIOS settings or configurations that a simple reboot might not, particularly if the computer is experiencing issues with its power management or startup sequence. A full shutdown removes power from all components, including the CMOS battery, which can reset the BIOS to its default settings if it’s been corrupted or if there’s a problem with the CMOS battery itself.”
That is a bit vague? What exactly gets cleared?
“Poweroff results in a more complete reset of the BIOS state than reboot”
Vague again… we need the details.
Clearly no, this isn’t a solution (for me).
I would suggest you just power off that machine and then boot it again. It’s probably easiest way. But I was curious how systemD handles reboot because my only machine with systemD has the issue I explained earlier and found this
soft-reboot
which should reboot only the userspace. Do a search, here’s the command to try it. I didn’t dare to try it because it’s not an issue to me to power off and power on.
sudo systemctl soft-reboot
After having a delicious homemade pizza 
and a suitable amount of red wine 
, I tried some more tests. Things I didn’t dare to try before, due to the lack of documentation. I really hate tapping out in the dark without any information. I already tried any combination of soft, hard, warm, cold, bios, acpi and force. But not pci! 
My solution works like a charm. Adding the kernel param reboot did the trick. Append reboot=pci to the variable GRUB_CMDLINE_LINUX in /etc/default/grub.
GRUB_CMDLINE_LINUX="reboot=pci"
Finally, a huge thanks to all contributors. Absolutely great being part of such a community!
That one did the trick, I’m quite sure!
Well done. We all enjoyed it to. This was a really good topic, it got people thinking.
I would call that a ‘fix’ rather than a ‘solution’… we still do not understand what is happening here.
That is why I could not help, I only drink rosé
Agree! With the summer temperatures down there, it’s a more suitable selection.