Today I could work on my OI machine again. I disabled xdm and enabled lightdm.As before the lightdm did not start, but now I had fresh logfiles. A Xorg.0.log does not exists, OK, because it was not started,
Now I followed @nipos hints to read the lightdm.org. And now the scales felt from my eyes:
Code:
[+0.01s] DEBUG: Adding default seat
[+0.01s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.01s] DEBUG: Seat seat0: Loading properties from config section Seat:
[+0.01s] DEBUG: Seat seat0: Starting
[+0.01s] DEBUG: Seat seat0: Creating greeter session
[+0.01s] DEBUG: Seat seat0: Failed to find session configuration lightdm-gtk-greeter
[+0.01s] DEBUG: Seat seat0: Failed to create greeter session
Failed to create greeter session!!! I figured out that the gtk-greeter was no longer installed.
So something crazy must have happened during my update, because I never ever have uninstalled the greeter.
OK, installing gtk-greeter was no problem, I disabled and enabled the lightdm once more - and the screen becomes black. Nothing more happensm but the machine was still alive and I could login via ssh to reboot.
And now everything was OK! The machine booted, the lightdm with all my old settings came up and started Xorg properly.
I did not unstand what has happened with my OI update, but thanks to your kind help everthing is OK now.
Berni, happy.