I recently wrote an article outlining how to remove the login screen user list in the KDE login screen. This article outlines the same steps, but specific to the GNOME login screen. The instructions here have been tested on Ubuntu 10.04 LTS as well as Ubuntu 9.10. If you would prefer to remove the user list from your login screen and require the username be entered in combination with the password, these instructions will achieve just that.
GDM Changes
I believe it was with Ubuntu 9.10 that the GDM login manager was rewritten and the previous configuration options removed. I know there was a lot of upset about that when it happened. The functionality seemed to be the same, but the configuration options that users had grown used to were now gone. It seems, however, that there are still some settings that can be changed. Perhaps not quite as many, but one of the important ones is still available. If slightly obscure.
Updating Configuration
There are two methods of updating this configuration. There is the command-line one-liner, which I like for it’s quick and easy use. There is also the graphical method. I’ll outline both below. You can follow whichever you feel most comfortable with.
Command Line : gconftool-2
To disable the login screen user list in Ubuntu 10.04, simply run the following command, entering your password when prompted:
sudo -u gdm gconftool-2 --set --type boolean /apps/gdm/simple-greeter/disable_user_list true
The next time you log in you’ll be prompted to enter your username and password, instead of selecting your username from a list.
Graphical Method : gconf-editor
To disable the login screen user list in Ubuntu 10.04 graphically, run the following command and then navigate to the proper key=value pair setting.
sudo -u gdm gconf-editor
Navigate to /apps/gdm/simple-greeter.
Check the box that says “disable user list”, setting the value to true.
disable ubuntu login user list
Whichever method you choose, you’ll end up with the same result. Disabling the list of users at the login screen. I prefer my machine to require the username + password combination. No reason in telling everyone who the machine belongs to, and removing half of the security of the login mechanism.
I am interested in hearing your thoughts on the security vs usability of a user list at login. Do you agree with me or disagree?