System freezes several times a day

[Jan Martin Krämer]

Hi everyone,

I have been using Qubes 3.2 for a while. After my harddrive crashed I got a new harddrive and had to reinstall Qubes and I think pretty much after that time it started freezing. The entire system goes from "perfectly fine" to a state where the screen looks normal, but the sound gets stuck in a one second long loop and the system no longer responds to any keypres, the mouse doesn't react, it is completely 100% frozen.

This happens several times a day now and turning off the power is the only thing I can do. Reinstalling 3.2 from scratch didn't fix it.

I have no idea how to diagnose the problem so I need help with that. Which log files should I provide, ...?

Best regards,
Jan

[filtration]

The entire system goes from "perfectly fine" to a state where the screen
looks normal, but the sound gets stuck in a one second long loop and the
system no longer responds to any keypres, the mouse doesn't react, it is
completely 100% frozen.
>
> This happens several times a day now and turning off the power is the only thing I can do. Reinstalling 3.2 from scratch didn't fix it.
>

I had temporary lockups that turned out to be related to a USB 3.0
(XHCI) controller and my USB mouse. Entire VMs would freeze until I
switched to Dom0 and back, IIRC. I changed some settings in BIOS so
everything was only EHCI and that fixed my problem.

It may not be anything in Qubes; It may be memory errors or an
overheating processor. Try running Memtest (freeware) for the memory.
Check for and blow out any dust buildup in your computer. I don't know
of an easy way to check temps within Qubes, but your BIOS ought to give
some indication.

[Jan Martin Krämer]

Am Montag, 25. September 2017 16:50:06 UTC+2 schrieb filtration:
> The entire system goes from "perfectly fine" to a state where the screen
> looks normal, but the sound gets stuck in a one second long loop and the
> system no longer responds to any keypres, the mouse doesn't react, it is
> completely 100% frozen.
> >
> > This happens several times a day now and turning off the power is the only thing I can do. Reinstalling 3.2 from scratch didn't fix it.
> >
>
> I had temporary lockups that turned out to be related to a USB 3.0
> (XHCI) controller and my USB mouse. Entire VMs would freeze until I
> switched to Dom0 and back, IIRC. I changed some settings in BIOS so
> everything was only EHCI and that fixed my problem.

I will try that. This is a different behaviour however as it is not single VMs that freezes, it literally is everything. Leaving Xorg and going to a console doesn't work, nothing I do has any effect. I am not sure if magic sysrq is enabled on qubes, I guess I would have to test it while it is still working, but if it is, it also didn't work.

> It may not be anything in Qubes; It may be memory errors or an
> overheating processor. Try running Memtest (freeware) for the memory.
> Check for and blow out any dust buildup in your computer. I don't know
> of an easy way to check temps within Qubes, but your BIOS ought to give
> some indication.

It is not a temperature problem, they are far below the standard temperatures even. I will run a memory test and report back if that can be the problem.

[Marcus Linsner]

On Monday, September 25, 2017 at 5:35:44 PM UTC+2, Jan Martin Krämer wrote:
> I am not sure if magic sysrq is enabled on qubes, I guess I would have to test it while it is still working, but if it is, it also didn't work.

On dom0, looks like only the sync command(sysrq+s) of sysrq is enabled by default:

[ctor@dom0 ~]$ grep -nH sysrq -- /usr/lib/sysctl.d/* /etc/sysctl.d/*
/usr/lib/sysctl.d/50-default.conf:16:# Use kernel.sysrq = 1 to allow all keys.
/usr/lib/sysctl.d/50-default.conf:18:kernel.sysrq = 16
/etc/sysctl.d/95-sysrq.conf:1:kernel.sysrq=1

I actually had to enable all by creating /etc/sysctl.d/95-sysrq.conf (as seen above).

All info from here: https://www.kernel.org/doc/Documentation/admin-guide/sysrq.rst

- 0 - disable sysrq completely
- 1 - enable all functions of sysrq
- >1 - bitmask of allowed sysrq functions (see below for detailed function
description)::

2 = 0x2 - enable control of console logging level
4 = 0x4 - enable control of keyboard (SAK, unraw)
8 = 0x8 - enable debugging dumps of processes etc.
16 = 0x10 - enable sync command
32 = 0x20 - enable remount read-only
64 = 0x40 - enable signalling of processes (term, kill, oom-kill)
128 = 0x80 - allow reboot/poweroff
256 = 0x100 - allow nicing of all RT tasks