Si ça se trouve, ni gdm, ni kdm ni xdm ne sont installés. Or, c'est ce que veut lancer le runlevel 5. tiens, exemple chez moi, c'est fait comme ça :
# GNOME's session manager is another choice:
#elif [ -x /usr/bin/gdm ]; then
if [ -x /opt/gnome/bin/gdm ]; then
exec /opt/gnome/bin/gdm -nodaemon
# KDE's kdm is the default session manager. If you're got this, it's the
# one to use.
elif [ -x /opt/kde/bin/kdm ]; then
exec /opt/kde/bin/kdm -nodaemon
# If all you have is XDM, I guess it will have to do:
elif [ -x /usr/X11R6/bin/xdm ]; then
exec /usr/X11R6/bin/xdm -nodaemon
fi
# error
echo
echo "Hey, you don't have KDM, GDM, or XDM. Can't use runlevel 4 without"
echo "one of those installed."
sleep 30
# All done.
Donc si il ne trouve pas un des 3, il ne va pas faire grand'chose.