How to change Display Manager from SDDM to LightDM on Plasma Tumbleweed

English Install/Boot/Login
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So… because of this long lasting bug (s): Bug 1207906 – Wayland crashes when automatic authentication via SDDM with Wayland is enabled.

I can’t autologin into Plasma/Wayland with SDDM. I’ve been googling as to how to switch my display manager to LightDM, but information on that is lacking. (I have installed LightDM.) This site:

https://www.suse.com/support/kb/doc/?id=000016701

Advises using YAST, but the drop down field is blanked out. There’s no option to choose LightDM. So YAST won’t work. I’ve looked in /etc/sysconfig/displaymanager but there’s no “DISPLAYMANAGER=” line. Is it simply a matter of inserting this line? DISPLAYMANAGER=lightdm or am I going to bork something by doing this? Thanks!

1 Like
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In Leap as root:

update-alternatives --config default-displaymanager 
Es gibt 5 Auswahlmöglichkeiten für die Alternative default-displaymanager (welche /usr/lib/X11/displaymanagers/default-displaymanager bereitstellen).

  Auswahl      Pfad                                  Priorität Status
------------------------------------------------------------
* 0            /usr/lib/X11/displaymanagers/sddm      25        automatischer Modus
  1            /usr/lib/X11/displaymanagers/console   5         manueller Modus
  2            /usr/lib/X11/displaymanagers/gdm       25        manueller Modus
  3            /usr/lib/X11/displaymanagers/lightdm   15        manueller Modus
  4            /usr/lib/X11/displaymanagers/sddm      25        manueller Modus
  5            /usr/lib/X11/displaymanagers/xdm       10        manueller Modus
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Also! So einfach ist es. Vielen dank. :slight_smile:

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Those instructions are out-of-date. You can use

Yast → Miscellaneous → Alternatives

5

Thanks! Next I was looking for the configuration file? Wanted to set that to autologin and Wayland. Sorry to be so clueless.

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Edit: Seems like it’s normally under etc/lightdm/lightdm.conf. But can’t find it there.

Have found other lightdm.conf files but none of them with a line specifying the display server.

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That is different question so start new topic with clear subject.

I already told you that “usual” way to configure autologon on openSUSE is to use YaST user management module and this will be respected by all display managers. You do not need to know and mess around with display manager specific configuration files (bugs withstanding). And lightdm should respect last user session.

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//I already told you that “usual” way to configure autologon on openSUSE is to use YaST user management module and this will be respected by all display managers. //

Yes, I know that’s what you told me, but your information is unfortunately incorrect. For instance, I’ve tried setting Wayland as the default display server through Yast, using LightDM, but still end up with X11. The simplest thing would be to edit the lightdm.conf file, if it exists. But thank you.

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Sigh!

Configure autologin with Yast.

If you are using “lightdm”, and the autologin takes you to X11, then simply logout. That should give you a login screen where you can choose Wayland. And “lightdm” should remember that for future logins.

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Thank you, but don’t cop an attitude.

It’s not my fault the SDDM bug hasn’t been fixed after five years. It’s not my fault YaST doesn’t work as advertized. And its not my fault the openSUSE man pages are out of date. And it’s not my fault the lightdm.conf file isn’t where every google search claims it is. And nobody can tell me where it is or if it even exists any longer. I love openSUSE. I’m just trying to sort out a relatively minor problem, and don’t need the attitude. Thanks again, though.

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Configuration shipped by distribution is in /usr/share/lightdm/lightdm.conf.d and local changes are in /etc/lightdm/lightdm.conf(.d) and it is this way in any other distribution using lightdm.

Because it is rather unclear what you are asking. You built some picture in your head but we are not aware of it and do not know what you mean with your questions. Anyway, /etc/lightdm/lightdm.conf is entirely optional and need not exist. I do not know why you are so fixed on it.

And once more - if you have questions how to configure lightdm you really should start new topic with questions how to configure lightdm.

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There is no need to configure LightDM. In an effort to assist I just installed the LightDM display manager and selected it with ‘update-alternatives’. At the login screen it is possible to choose ‘Plasma (X11)’ or Plasma (Wayland)’ at top right of screen. The session type should remain as chosen following a reboot. The previous session state is stored in /var/lib/lightdm/.cache/lightdm-gtk-greeter/state.

For Plasma (X11), /var/lib/lightdm/.cache/lightdm-gtk-greeter/state contains…

[greeter]
last-user=****
last-session=plasma5

For Plasma (Wayland), it contains…

[greeter]
last-user=****
last-session=plasmawayland

You can confirm the session type from a terminal with

echo $XDG_SESSION_TYPE