I recently switched a Fedora host from the GNOME window manager to KDE. This exercise allowed me to familiarize myself with how X and the various window managers are organized on Fedora hosts, and I thought I would jot down how to switch between window managers for future reference.
When a Fedora host is booted into run-level 5, the following initab entry will cause the X server and Window manager to start:
# Run xdm in runlevel 5
x:5:respawn:/etc/X11/prefdm -nodaemon
The prefdm script uses the /etc/sysconfig/desktop file to control which window manager (KDE or GNOME) is started, as you can see in the following code snippet from the script:
preferred=
if [ -f /etc/sysconfig/desktop ]; then
. /etc/sysconfig/desktop
if [ "$DISPLAYMANAGER" = GNOME ]; then
preferred=gdm
elif [ "$DISPLAYMANAGER" = KDE ]; then
preferred=kdm
elif [ "$DISPLAYMANAGER" = XDM ]; then
preferred=xdm
fi
fi
So to set the default window manager to GNOME, you can set the DISPLAYMANAGER variable to GNOME:
$ echo "DISPLAYMANAGER=GNOME" >> /etc/sysconfig/desktop
To use KDE, you can set the DISPLAYMANAGER variable to KDE:
$ echo "DISPLAYMANAGER=KDE" >> /etc/sysconfig/desktop
I dig the fact that Fedora and CentOS Linux servers control application settings through configuration files in /etc/sysconfig. This makes it easy to adjust application settings, and ensures that a package update won’t whack your customizations! Nice!