If you’re looking to customize your GDM login on Ubuntu 10.04, 10.10 and I’m sure in the near future 11.04, it’s pretty straight forward and easy to do. There are some important notes at the end of this. So read through or, I warned you.

Typically, I logout first, then ctrl+alt+f1 and use that tty when doing this.

Anyway…

$ sudo cp /usr/share/applications/gnome-appearance-properties.desktop /usr/share/gdm/autostart/LoginWindow/

If you’re already logged out and on another tty… (don’t kill gdm when you’re logged into a gui gnome session, be logged out first)

$ sudo /etc/init.d/gdm stop
# WAIT FOR A SECOND OR TWO
$ sudo /etc/init.d/gdm start

After hitting enter on start, it should snap you back to the login window. You may have noticed a warning that gdm is a service and should be stopped/started using service gdm stop/start but personally, I don’t care. Also, I don’t issue a restart command to gdm because I’ve found that you can initiate multiple X sessions.

In the future, I think they want you to really start using “service” though since that is where the transition is headed.

Anyway… some important notes:

You’ll find that all of your themes, backgrounds, etc from your home directory do not exist on this appearance preferences window. Well, everything that you want available to the gdm login should be in the following directories in the same manner that you would in your home directory. Also, any themes, icons, fonts etc will need chmod 755.

/usr/share/themes
/usr/share/icons
/usr/share/backgrounds
/usr/share/fonts

This one is really important, if you use metacity (personally, emerald is way better) but like I was saying, if you use metacity, DO NOT set a window border from the GDM login appearance preferences. It will override your user session window border. I have not looked into how to reset it really (because I use emerald), but I did find that playing with window managers through fusion-icon (apt-get install fusion-icon) seemed to reset it.

If you enable desktop effects (compiz), it will not persist to your next login. I actually plan on making another post here in the near future on how to make compiz persistent

Update: Was just checking out omgubuntu and saw this post about a GUI that can do this. Apparently there is also gdm2setup which has a PPA. Typically I don’t look for these things since I do most things in the terminal, but I guess it could make life easier for some.