Random freezes on 19.04, unsure which logs to check

Enable systemd multi-boot message logs

The best solution is to enable multi-boot message logging and then displaying the last messages of the previous boot:

$ journalctl -xe -b-1

Nov 11 23:12:07 alien systemd[1]: Reached target Shutdown.
-- Subject: Unit shutdown.target has finished start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit shutdown.target has finished starting up.
-- 
-- The start-up result is done.
Nov 11 23:12:07 alien systemd[1]: dev-disk-by\x2dpartlabel-Basic\x5cx20data\x5cx20partition
Nov 11 23:13:37 alien systemd[1]: dev-disk-by\x2duuid-b4512bc6\x2d0ec8\x2d4b17\x2d9edd\x2d8
Nov 11 23:13:37 alien systemd[1]: Deactivated swap /dev/disk/by-uuid/b4512bc6-0ec8-4b17-9ed
-- Subject: Unit dev-disk-by\x2duuid-b4512bc6\x2d0ec8\x2d4b17\x2d9edd\x2d88db0f031332.swap 
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit dev-disk-by\x2duuid-b4512bc6\x2d0ec8\x2d4b17\x2d9edd\x2d88db0f031332.swap has finis
Nov 11 23:13:37 alien systemd[1]: dev-disk-by\x2duuid-b4512bc6\x2d0ec8\x2d4b17\x2d9edd\x2d8

In your case the messages won't show a normal shutdown but rather the last recorded messages just before the system crashed.

Analyzing the messages you found so far

The first error message is addressed here:

• New alert keeps showing up: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001

The solution is to use:

It seems that my system had the old config in the place, resulting in a conflict between two services: resolvconf and systemd-resolved.

The symlink /etc/resolv.conf pointed to ../run/resolvconf/resolv.conf

Changing it to point to /run/systemd/resolve/resolv.conf which is managed by systemd, fixed it for me.

The second error message is generated by nvidia:

• PRIME offloading: Unable to run chrome

The answers posted are only helpful for the software developer, not the end user. For end users running chrome other solutions exist:

• Chrome Routinely Crashing

System lockups can be notoriously hard to diagnose, particularly when nothing shows in syslog. You could check journalctl as suggested in the other answer but my guess is it won't show anything more informative.

If you are able to find a way to reliably trigger the freeze, then running dmesg --follow --human in a window may show something useful. However, much of the time the freeze occurs so suddenly nothing actually gets logged. And a lot of time these 'random freezes' are difficult to narrow to any specific cause.

System freezes can be caused by an issue in the hardware itself (e.g. bad memory, overloaded power supply, ...), a defected in the BIOS, or a bug in the kernel or it's hardware drivers (GPU drivers particularly). Sometimes it's most time efficient to first try upgrading/downgrading the kernel, then see if there is a BIOS update available and if so update it, then do some hardware diagnostics and/or replacements.

GPU lockups are a common type of system freeze. For Intel graphics there are tools to get dumps off the video card itself following a freeze (see docs for intel-gpu-tools), but it can be hit or miss to get useful enough information. Often best case is to keep updating your bios, kernel, and/or hardware until the issue goes away.