After Nvidia driver install, LightDM won't start automatically

Question

I did a clean install and after installing updates and drivers (Nvidia VGA) for a 460GTX, I'm shown a black screen with various Stopping/Starting messages. The last of these messages is different (this time it's "Stopping save kernel messages") every time I try and boot up the system. Logging into tty1 and doing sudo startx or start lightdm works. Nvidia drivers seem to be working.

Some things I've tried or noticed.

• Problem seems to start after installing Nvidia drivers.
• cat /etc/X11/default-display-manager spits out /usr/sbin/lightdm.
• sudo dpkg-reconfigure lightdm gives me DPKG_MAINTSCRIPT_NAME and PACKAGE missing.
• Also restored lightdm settings and reinstalled it.

Solution 1

I had a very similiar problem just a few minutes ago: I downloaded the current driver from nvidia support site. Installation script run without problems. However, the boot process stopped shortly after the message for starting lightdm.

The machine was completely unresponsive, only frozen black screen with the [Starting] messages. Fortunately the network was working and I could log in remotely with ssh.

/var/log/lightdm/lightdm.log revealed that the X server exited with an error. /var/log/lightdm/x-0.org complained about different versions of the nvidia driver and the nvidia kernel module.

I reinstalled the nvidia driver from ubuntu:

sudo apt-get install nvidia-current
sudo reboot

Everything works fine again, but of course it's still the old driver.

Solution 2

I was also getting strange messages after a removing nVidia settings using:

sudo apt-get remove --purge nvidia-*

Then installing nvidia-current:

sudo apt-get install nvdia-current

Ubuntu got stuck at giving messages ieee80211:phy ...

This thread helped me Failed to Start the X server.

In summary:

1. Login to any tty as root Ctrl+Alt+F1~F6

2. Save a backup of your current xorg.conf file as:

   cp /etc/X11/xorg.conf /etc/X11/xorg_backup.conf
   

3. Run command

   sudo Xorg -configure
   

4. Copy new configuration file e.g /root/xorg.conf.new to /etc/X11/xorg.conf:

   cp /root/xorg.conf.new /etc/X11/xorg.conf
   

5. Enter command startx

After reboot, if every thing works fine, remove the backup file xorg_backup.conf of step (2).

Comments

[mfisch]

Assuming this is still happening, please post your lightdm logs from /var/log/lightdm/*