DevHeads.net

18.04 daily build "hang"

I downloaded and installed a daily build of bionic-desktop-amd64.iso yesterday
and found it to be unstable... the X interface became unresponsive other
than the ability to move the mouse. This happened using the default
environment and in plasma with and without Wayland. I have 4 monitors with
an nvidia graphics card.

VGA compatible controller: NVIDIA Corporation GK106 [GeForce GTX 660] (rev
a1)

I didn't try to install the proprietary driver for it. I understand that
daily builds can be unstable, so my question is, should I bother trying to
report this problem and if so, how can I get any useful debug info from a
system that is non-responsive other than the ability to move the mouse? Or
is this kind of bug typical at this stage in testing and I should wait and
try again in a month?

Thanks,

Dave

Comments

Re: 18.04 daily build "hang"

By Robert Heller at 02/13/2018 - 14:02

About getting "useful debug info from a system that is non-responsive other
than the ability to move the mouse": can you do any of these:

ssh into the machine from another computer?
did you try installing as a non-graphical startup/login?
were you able to switch to another virtual console?

*I* *always* install Linux without the graphical boot or login. ALL of *my*
linux machines come up to a black console login, and generally with the
verbose boot up. I use startx/xinit to start the GUI, if that is something I
need, *after* I have logged in.

Re: 18.04 daily build "hang"

By David L at 02/13/2018 - 14:26

I didn't try that yet either... would that be ctrl-alt-F2? Again, what
commands would I run to capture useful data on a partially responsive
graphical session?

Thanks again,

Dave

Re: 18.04 daily build "hang"

By Robert Heller at 02/13/2018 - 15:13

Looking at /var/log/Xorg.0.log could be enlightening, otherwise, yes looking
at log files can could be useful. Seeing what sort of state X is in (S or D
or R or what). Seeing what kill X or kill -9 X does, etc.

*Excecpt* you could verify that it is indeed the *GUI* subsystem that is
borked. Also, you can separate the GUI *login* from the GUI itself. And you
can try ctrl-alt-backspace to kill X11 and return to the console terminal and
then look at log files, etc. Doing ctrl-alt-backspace with a GUI login, just
restarts the GUI login and if the *GUI* is borked, that can be fruitless.

ctrl-alt-F[1234567]

Usually ctrl-alt-F7 would be the GUI screen, but sometimes ctrl-alt-F1 is.
ctrl-alt-F2 is likely be safe and will give you a terminal console.

Looking at /var/log/Xorg.0.log and/or various other log files.

(The commands cat, more, less, tail, or vi would be your friends here.)

Looking at /var/log/Xorg.0.log may also be cluefull in terms of what you can
try putting in /etc/X11/xorg.conf.d/ to deal with possible problems
(incompatable hardware, workarounds for buggy video drivers, etc.). And if
some hack there "works" then that can be helpful for the people writing those
video drivers in terms of what they can do to fix the video drivers.

Re: 18.04 daily build "hang"

By David L at 02/13/2018 - 22:39

Additionally, after I installed kubuntu-desktop and logged in under plasma
with Wayland and then rebooted and tried to log into a standard Ubuntu
session, I got this error window on a black screen:

"unsupported number of arguments (4); falling back to default session"

Another problem I saw was that one of my monitors is in portrait mode and
when I move the mouse across the right boundary, I see two mouse pointers
for a while... one where it should be in the window the to right and one
where it would be if it was in landscape mode.

Cheers,

Dave

Re: 18.04 daily build "hang"

By Liam Proven at 02/14/2018 - 03:09

Does it freeze before or after login?

If before, how did you install KDE?

Try booting with the ``nomodeswitch'' kernel parameter.

You can also try the nVidia drivers if you can get to a console -- no
harm if it's already broken.

Install an ssh server, then you can connect from another machine and
have a poke around and see what's going on.

Re: 18.04 daily build "hang"

By David L at 02/14/2018 - 03:45

Re: 18.04 daily build "hang"

By David L at 03/16/2018 - 15:33

One time when it partially hung with the nouveau driver, I could move the
mouse, but no other sign of life...even the keyboard caps lock button was
not changing the caps lock light, I was still able to ssh into it.

So I assume this is a nouveau driver bug with my video card:
04:00.0 VGA compatible controller: NVIDIA Corporation GK106 [GeForce GTX
660] (rev a1)