LightDM installation instead KDM
Switch from KDM to LightDM on existing KDE installations.
Starting with the 2013.2 release "December" siduction uses LightDM as login manager for KDE. If you want to switch to the same on an older system still using kdm, you can easily do this.
An overview of existing LightDM packages, namely greeters, shows apt-cache search lightdm. If we want the kde-greeter for KDE we just do(ridersonthestorm as example):
apt-get update apt-get install lightdm lightdm-kde-greeter siduction-art-lightdm-ridersonthestorm
(Note: siduction default would be lightdm-gtk-greeter instead, so that is what is officially supported. Advantage of kde-greeter is integration in KDE's systemsettings, but some people reported this package to be buggy).
If you are asked to configure the default display manager, choose lightdm. The alternatives-system sets the default greeter to gtk, so after installation you have to choose the lightdm-kde-greeter option at
update-alternatives --config lightdm-greeter
After installation, go to KDE systemsettings -> login screen, here is the configuration for LightDM. Select a background picture, a theme (userbar or classic), or configure autologin and guestlogin on the advanced-tab.
If your system successfully reboots using lightdm, you might remove kdm
apt-get purge kdm
Some wikis (arch, ubuntu) mention the tool lightdm-set-defaults to configure LightDm instead of directly editing /etc/lightdm/lightdm.conf, which in debian sid and testing has to be run from the path:
- 32-bit: /usr/lib/i386-linux-gnu/lightdm/lightdm-set-defaults
- 64-bit: /usr/lib/x86_64-linux-gnu/lightdm/lightdm-set-defaults
-  https://wiki.archlinux.org/index.php/LightDM#Optional_configuration_and_Tweaks
-  https://wiki.ubuntu.com/LightDM#Advanced_Options