Killing off remaining processes
dracut Warning: Unmounted /oldroot
Rebooting
(note that the above was manually copied from the screen).
The problem is that it never actually reboots. It just hangs at that point.
If I instead attempt a shutdown, I get the same except that the last line is “Powering off”.
I have rebuilt the “initrd” but that did not help.
I can manually power off. And when I boot up again, I can look at the output of “dmesg”. I did a search there for “fsck” and found only one entry, which was for starting an fsck service. So it looks as if the file systems were all umounted before the hang.
I’m currently using Plasma-X11 with SDDM, but I don’t think that is relevant. A command line shutdown or CTRL-ALT-DEL does same thing. And “logout” from KDE works.
Since “dracut” gave a warning that “/oldroot” is unmounted, that suggests a possible software issue. I’ll note that I did not have this problem with Leap 15.6.
The only reason I suspect ACPI (which would probably be some kind of issue with the kernel, so your rebuilding the initrd makes sense), is that once the filesystems are unmounted, there’s not a whole lot left in the process, and the hardware should be getting the signal to powercycle or poweroff.
But just looking through my own dmesg and journal, I’m not sure what I should be looking for or seeing anything jumping out at me.
I did have a machine that used to do this, years ago, because it had a half-arsed non-standards-compliant BIOS, but if this was working fine with 15.6, I doubt that’s the issue.
I got to 16.0 with an online upgrade from an earlier Leap 15.5 system. There was a kernel left over from 15.5 (kernel 5.14.21-150500.55.65). So I tried booting that. And with that kernel, reboot works as it should. So this is looking like a kernel bug.