Login Screen Across All Sessions

[Corelogik]

I have Ubuntu 12.04 running fine with Cinnamon desktop. Recently I installed MDM window manager to try it out, discovered I didn't like and went back to lightDM.

Everything went fine until reboot, I still got the MDM login screen. I ended up having to edit lightdm.conf to reset to the unity greeter login screen.

This is what I had to change it to;


[SeatDefaults]
user-session=cinnamon
greeter-session=unity-greeter


Now login screen is restored but I am left with a couple of questions. I have regular Ubuntu, Gnome Shell and Cinnamon installed. Along with all their 2D versions.

1.) Will my edit work across all sessions if I decide to change again, or is that only going to work for Cinnamon?

2.) If the login is just for Cinnamon, how would I set it for all sessions? What would I need to put in for "user-session"?

I realize I could test this myself by simply logging out and choosing a new session, but I prefer to not interrupt my work to do that. Also, that wouldn't help with figuring out what to put in for "user-session" if I need to do something else.

Thank you in advance for your input and advice.

[zombifier25]

The session is started by the login manager, not vice versa, so yes for 1 and no need for 2.
(also, the user-session config in lightdm.conf sets the default session for newly created users on the system)

But I'm rather curious. How did you revert back to LightDM without running

sudo dpkg-reconfigure lightdm
Dismiss this if you DID run the command.

It's probably important that you log out later to check that you did in fact revert the login manager back to LightDM.

[Corelogik]

The session is started by the login manager, not vice versa, so yes for 1 and no need for 2.
(also, the user-session config in lightdm.conf sets the default session for newly created users on the system)

But I'm rather curious. How did you revert back to LightDM without running

sudo dpkg-reconfigure lightdm
Dismiss this if you DID run the command.

It's probably important that you log out later to check that you did in fact revert the login manager back to LightDM.

I did run
sudo dpkg-reconfigure lightdm and then logged out and back in a couple of times. Even one complete reboot. However it kept dumping me into the login screen from MDM until I edited the conf file. Any how, as long as it will use lightDM from here on out if I change the DE at login, I guess I'm good.

I'm going to assume from your post that
sudo dpkg-reconfigure lightdm SHOULD, take care of it and all I need to do after is a relog or reboot. At least I know how to fix it if I end up stuck again.

TYVM!