Veröffentliche die Konfigs von GDM und LightDM, möglicherweise kann man etwas sehen.
Da wurde ja leider viel geändert, war früher einfacher für den Normalbürger.
Ich hoffe das ist was du meintest:
gdm3:
# GDM configuration storage
#
# See /usr/share/gdm/gdm.schemas for a list of available options.
[daemon]
# Uncomment the line below to force the login screen to use Xorg
#WaylandEnable=false
# Enabling automatic login
# AutomaticLoginEnable = true
# AutomaticLogin = user1
# Enabling timed login
# TimedLoginEnable = true
# TimedLogin = user1
# TimedLoginDelay = 10
[security]
[xdmcp]
[chooser]
[debug]
# Uncomment the line below to turn on debugging
# More verbose logs
# Additionally lets the X server dump core if it crashes
#Enable=true
lightDM:
# LightDM - light Display Manager
#
# The display manager service manages the X servers running on the
# system, providing login and auto-login services
#
# based on gdm upstart script
description "LightDM Display Manager"
author "Robert Ancell <robert.ancell@canonical.com>"
start on ((filesystem
and runlevel [!06]
and started dbus
and plymouth-ready)
or runlevel PREVLEVEL=S)
stop on runlevel [016]
respawn
respawn limit 2 15
emits login-session-start
emits desktop-session-start
emits desktop-shutdown
script
if [ -n "$UPSTART_EVENTS" ]
then
# Check kernel command-line for inhibitors, unless we are being called
# manually
for ARG in $(cat /proc/cmdline); do
if [ "$ARG" = "text" ]; then
plymouth quit || :
stop
exit 0
fi
done
[ ! -f /etc/X11/default-display-manager -o "$(cat /etc/X11/default-display-manager 2>/dev/null)" = "/usr/bin/lightdm" -o "$(cat /etc/X11/default-display-manager 2>/dev/null)" = "/usr/sbin/lightdm" ] || { stop; exit 0; }
if [ "$RUNLEVEL" = S -o "$RUNLEVEL" = 1 ]
then
# Single-user mode
plymouth quit || :
exit 0
fi
fi
exec lightdm
end script
post-start script
sleep 5
clear > /dev/tty7
end script
post-stop script
clear > /dev/tty7
sleep 1
if [ "$UPSTART_STOP_EVENTS" = runlevel ]; then
initctl emit desktop-shutdown
fi
end script