Ubuntu – Ubuntu 14.04 not coming out of lock, sometimes

14.04lock-screennouveau

I have a clean 14.04 Ubuntu installation on a dell precision T5400 with a NVIDIA card. The system is updated and upgraded. When the system locks after 5 minutes, the system does not show the login with password screen. But I can still ses the windows of the apps I had open before the lock. I can actually move the mouse pointer to the left and see the hide/unhide animation for the tool bar. If a plug a usb stick I can see a new nautilus window. I can restart the desktop by restarting the lightdm process, but I loose all the windows and process I had open of course.

Any ideas how to debug this problem? somebody has a solution?

Best regards,

After looking at the "syslog" (after a recommendation from Simptnon) I discovered that the gnome session stops with "Fatal IO error 11"

May  5 11:24:34 slozano-01 kernel: [233478.298064] usb 1-5.3: USB disconnect, device number 9
May  5 11:24:34 slozano-01 colord: device removed: sysfs-(null)
May  5 11:24:34 slozano-01 colord: device removed: sysfs-samsung-Galaxy_Nexus
May  5 11:29:33 slozano-01 kernel: [233776.995035] nouveau E[compiz[4535]] fail ttm_validate
May  5 11:29:33 slozano-01 kernel: [233776.995043] nouveau E[compiz[4535]] validate vram_list
May  5 11:29:33 slozano-01 kernel: [233776.995100] nouveau E[compiz[4535]] validate: -12
May  5 11:29:33 slozano-01 kernel: [233777.254919] nouveau E[compiz[4535]] fail ttm_validate
May  5 11:29:33 slozano-01 kernel: [233777.254927] nouveau E[compiz[4535]] validate vram_list
May  5 11:29:33 slozano-01 kernel: [233777.254982] nouveau E[compiz[4535]] validate: -12
May  5 11:43:18 slozano-01 colord: device removed: xrandr-Dell Inc.-DELL 2009W-KM50984O435L
May  5 11:43:18 slozano-01 colord: device removed: xrandr-Dell Inc.-DELL 2009W-KM50984O448L
May  5 11:43:18 slozano-01 colord: Profile removed: icc-dc7cf53b156187281507a2bdfcabad3c
May  5 11:43:18 slozano-01 colord: Profile removed: icc-d09afdda29e099d929b13d54c0f5e976
May  5 11:43:18 slozano-01 gnome-session[4340]: Gdk-WARNING: gnome-session: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.#012

This maybe is related to bug: "https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers/+bug/999191". I will remove the nvidia drivers from the system and see if that solves the problem.

Best Answer

If you can't get in to a terminal then you could use:

  • Ctrl+Alt+F2 - To access the core terminal;
  • Ctrl+Alt+F7 - to exit and return to the GUI;

If you're running nautilus you can restart a session by:

sudo killall -9 nautilus && nautilus &

You should first get the process ID of the failed session (gnome-shell/nautilus):

ps aux | grep gnome

Will return something like the following (perhaps lesser processes):

fs11# ~ $ ps aux | grep gnome
ash       2568  0.0  0.1 523420  4300 ?        SLl  Mar17   2:31 /usr/bin/gnome-keyring-daemon --daemonize --login
ash       2578  0.0  0.0 438164  2992 ?        Ssl  Mar17   6:11 gnome-session --session=gnome
ash       2625  0.0  0.0  12616    32 ?        Ss   Mar17   0:07 /usr/bin/ssh-agent /usr/bin/dbus-launch --exit-with-session /usr/bin/im-launch gnome-session --session=gnome
ash       2628  0.0  0.0  24468     0 ?        S    Mar17   0:00 /usr/bin/dbus-launch --exit-with-session /usr/bin/im-launch gnome-session --session=gnome
ash       2646  0.0  0.0 124856  1644 ?        Sl   Mar17   0:15 /usr/lib/at-spi2-core/at-spi2-registryd --use-gnome-session
ash       2666  0.0  0.3 966324 13728 ?        Sl   Mar17  15:26 /usr/lib/gnome-settings-daemon/gnome-settings-daemon
ash       2698  1.1 19.8 2952084 805572 ?      SLl  Mar17 836:10 /usr/bin/gnome-shell
ash       2754  0.0  0.3 528620 15652 ?        Sl   Mar17   7:09 gnome-screensaver
ash       2762  0.0  0.0 420240  2036 ?        Sl   Mar17   0:01 /usr/lib/gnome-shell/gnome-shell-calendar-server
ash       2994  0.0  1.2 775312 49648 ?        Sl   Mar17  52:52 gnome-terminal
ash       2998  0.0  0.0  14836   400 ?        S    Mar17   0:00 gnome-pty-helper
ash      13051  0.0  0.0   9448   944 pts/10   S+   10:57   0:00 grep --color=auto gnome

Now you need to find the failed process:

  1. gnome-shell would usually be running /usr/bin/gnome-shell; OR
  2. nautilus would usually be running /usr/bin/naultilus;

Example:

ash       2698  1.1 19.8 2952084 805572 ?      SLl  Mar17 836:10 /usr/bin/gnome-shell

With the example above the process ID is 2698 - Now we're going to "gracefully restart" this process by sending a hang-up signal known as a HUP with the following command:

kill -HUP 2698

Conclusion

When I say "gracefully restart" - A hangup signal simply send a signal to the parent process. The phrase graceful(ly) essentially waits until the process has finished before sending the signal. So you're not actually restarting the process.

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