LightDM Fails to Load with (L)ubuntu Oneiric (11.10)

After my migration from default Ubuntu with Unity and Gnome3 to Lubuntu with LXDE and OpenBox, I realized I have managed to sacrifice beautiful LightDM, the new default login manager on 11.10 and instead, running not so pretty LXDM.

After realizing that LightDM is missing the first thing to do was obviously:

sudo apt-get install lightdm

Followed by:

sudo dpkg-reconfigure lightdm

sudo service lxde stop

sudo service lightdm start

Not much to my surprise on 11.10, LightDM didn't start. After a little digging through the log files located at /var/log/lightdm, I came across the following:

"lightdm can not write to /var/lib/lightdm/.Xauthority"

Time to check /var/lib/lightdm directory:

[11:13:26] user@machine:[/var/lib/lightdm]$ sudo ls -alh
total 44K
drwxr-x---  9  109  130 4.0K 2011-10-14 20:08 .
drwxr-xr-x 74 root root 4.0K 2011-10-17 16:56 ..
drwx------  4  119  136 4.0K 2011-10-14 15:28 .cache
drwx------  4  119  136 4.0K 2011-10-14 15:28 .config
drwx------  3  119  136 4.0K 2011-10-14 15:28 .dbus
-rw-------  1  119  136   16 2011-10-14 15:32 .esd_auth
drwx------  2  119  136 4.0K 2011-10-14 18:29 .gconf
-rw-------  1  119  136    0 2011-10-14 19:55 .goutputstream-54JJ3V
drwx------  2  119  136 4.0K 2011-10-14 15:28 .gvfs
drwxrwxr-x  3  119  136 4.0K 2011-10-14 15:32 .local
drwx------  2  119  136 4.0K 2011-10-14 16:22 .pulse
-rw-------  1  119  136  256 2011-10-14 15:32 .pulse-cookie
-rw-------  1  119  136    0 2011-10-14 20:08 .Xauthority

After checking /etc/passwd and /etc/group, it confirmed that somehow user-id 119 and groupd-id 136 has gone missing from my system. So, as a quick roll-back, I did the following:

sudo apt-get remove --purge lightdm

sudo mv /var/lib/lightdm /var/lib/lightdm.bak

sudo apt-get install lightdm

sudo service lxdm stop

sudo apt-get remove --purge lxdm

sudo service lightdm start

Voila, LightDM showed up with a nice log-in prompt. Re-installing LightDM, added a new user and group with ids 109 and 130 respectively. Also, the ls output in /var/lib/lightdm looks correct.

[11:33:08] user@machine:[/var/log/lightdm]$ sudo ls -al /var/lib/lightdm/
total 44
drwxr-x---  9 lightdm lightdm 4096 2011-10-18 11:14 .
drwxr-xr-x 74 root    root    4096 2011-10-18 11:15 ..
drwx------  4 lightdm lightdm 4096 2011-10-18 11:14 .cache
drwx------  3 lightdm lightdm 4096 2011-10-18 11:14 .config
drwx------  3 lightdm lightdm 4096 2011-10-18 11:14 .dbus
-rw-------  1 lightdm lightdm   16 2011-10-18 11:14 .esd_auth
drwx------  5 lightdm lightdm 4096 2011-10-18 11:15 .gconf
d?????????  ? ?       ?          ?                ? .gvfs
drwxrwxr-x  3 lightdm lightdm 4096 2011-10-18 11:14 .local
drwx------  2 lightdm lightdm 4096 2011-10-18 11:14 .pulse
-rw-------  1 lightdm lightdm  256 2011-10-18 11:14 .pulse-cookie
-rw-------  1 lightdm lightdm   49 2011-10-18 11:14 .Xauthority


Edit (20 Jan 2012):
I stumbled into another problem with LightDM after uninstalling gnome-settings-daemon. It looks like the background file to set for LightDM is requested through gnome-settings-daemon for some reason on my system. So, if you have the same problem, a quick apt-get install gnome-settings-daemon will solve the problem.