Shutdown Hang

[Marius Gedminas]

On Thu, Mar 09, 2017 at 09:36:24PM -0300, Renê Barbosa wrote:
> After upgrading my laptop (Dell Inspiron 5447) from 14.04 to Ubuntu GNOME
> 16.04.2 I can't shut down after a few hours using the system (4+ hours). It
> hangs in Plymouth and stays that way until I force the shutdown by pressing
> the Power Button.

Can you force a reboot/shutdown by using the magic SysRq key?  (Hold
down Alt+PrintScren, then type S, U, B to reboot or S, U, O to power
off, while still holding the Alt+PrintScreen.)

> It looks like this is a common bug (there are tons of questions on the
> Internet). I tried to fix it, but none of my attempts were effective.

I had experienced some fun with reboots taking a long time (20-40
*minutes*), which turned out to be due to swapoff being really slow.
But I see you already tried turning swap off, so it's not that.

> Already tried:
> 
> 1. Boot with acpi=force, acpi=noirq and pci=noacpi
> 2. Disable Swap
> 3. Run 'sync' before reboot or shutdown
> 4. Use another kernel version (4.7, 4.8, 4.9 and 4.10 from mainline)
> 5. Disabling USB 3.0
> 6. Disabling TLP
> 7. Install AMDGPU-PRO 16.60
> 
> The most interesting thing is: I can shutdown/reboot normally using 14.04
> and the kernel from Xenial HWE. Is It a systemd bug?

It does sound like systemd is waiting for some service to shut down, but
that service is taking a long time to shut down.

/usr/share/doc/systemd/README.Debian.gz has a section titled "Debugging
boot/shutdown problems".  You may want to use the method described there
to see what's actually going on during the shutdown procedure.

Regards,
Marius Gedminas
-- 
IBM motto: "TEN vowels? Don't you know vowels are scrd?"
		-- Linus Torvalds