/etc/sysconfig/display manager missing 'DISPLAYMANAGER" option

English Install/Boot/Login
1

Hi,
I had the chance to install LEAP 15 on my main desktop yesterday.
I installed xfce first and then I added plasma after the installation of LEAP 15 was finish.
Installation was a breeze, I finish it in maybe 20 to 30 minutes for xfce.
However this morning I went to YAST2 to replace my DISPLAYMANAGER from lightdm to sddm
and find out that that option was none in my installation.
I am just wondering if it was normal for LEAP 15 that the developers remove it or was there an error in my install.

This is the string that was missing in /etc/sysconfig/display manager

## Type:    string(kdm,xdm,gdm,wdm,entrance,console,lightdm,sddm)
## Default:    ""
#
# Here you can set the default Display manager (kdm/xdm/gdm/wdm/entrance/console).
# all changes in this file require a restart of the displaymanager
#
DISPLAYMANAGER="sddm"
## Path:    Desktop/Display manager
## Description:    settings to generate a proper displaymanager config
## Type:    yesno
## Default:    no

I manually added the above lines in /etc/sysconfig/display manager
before I was able to change my DISPLAYMANAGER.

2

… and did that work? AFAIK, it does not work anymore, so check your display manager switched.

Anway, that has been changed, and the method to choose display manager now and going forward is:

update-alternatives --config default-displaymanager
3

Always a good idea to read the release notes…

In the past, you could use /etc/sysconfig or the YaST module /etc/sysconfig Editor to define the login manager and desktop session. Starting with openSUSE Leap 15.0, the values are not defined using /etc/sysconfig anymore but with the alternatives system.

4

Hi,

It worked. Now I have sddm and the option is showing again in Yast2.
I just don’t know if it will work changing the DISPLAYMANAGER in yast2 again.
Thanks for responding to my post.

5

Hi,
Yep I didn’t read the release notes, and this is the first time I didn’t follow or read the news about the development of openSUSE.
It was only yesterday that I had the time on downloading the dvd iso and installed it after.

Anyway, when I tried adding those missing lines in /etc/sysconfig/displaymanager and change made sddm as the displaymanager it worked.
It even showed the options in yast2.
Any thoughts on this?
Thanks guys for the quick response. this forum is really awesome, lots of nice pro that immediately respond to help.

6

Only that doing so may not be guaranteed work in the future.

7

… and, I tried exactly that on one of my machines, wanting to switch to KDM, and although it showed as the OP says above in the file and in Yast, the display manager itself that was actually running was not the one I had thought I “switched to”, but was still LightDM.

It seems that entry and that file was ignored, and only the update-alternatives setting worked.

I do not know if that has changed, but I would suggest to the OP to check that the desired display manager really is in use, or if that interface just makes it seem so.

8

Yes, agreed.

This will reflect reality…

ls -l  /etc/alternatives/default-displaymanager
9

Because that YaST module reads what is in /etc/sysconfig and then shows it to the GUI user in a way a GUI users understands (well, it hopes so).
I assume (but never tried that) that you can add a file in /etc/config named foo and then (using one of the other files there as example, specially the lines that start with ##) adding an item named BAR with several possible values, etc. It will then show in yast. But it will not do very much like DISPLAYMANAGER will not do very much anymore as no program whatsoever will consult that configuration file.
There is no magic in computers!

10

Here is the output:

~> ls -l  /etc/alternatives/default-displaymanager
lrwxrwxrwx 1 root root 33 Jun 23 13:37 /etc/alternatives/default-displaymanager -> /usr/lib/X11/displaymanagers/sddm

I know what lightdm login screen look like compare to sddm, sddm has a lot of bling-blings, and
thas the one I have now after manually adding those line I mentioned from my original post.:slight_smile:
So if it didn’t change from lightdm to sddm my login screen would have been the same when I installed Leap 15.

11

Thanks,
Please see my above post with quote from Diano’s post.
Well, the command shows what I am using now.
What do you think? Is there something wrong with my install because I was able to change to sddm
but yours did not?

On a side note, after I downloaded the iso I checked the sha256 and it was okay.
However I run out of blank dvd disk, it was just fortunate that I found one old dvd-rw and I used
and overwritten the original content with Leap 15.

Been away for a while here in this forum, I noticed that you are now part of the global moderating team.
Congrats, and please keep up the good work helping us.

12

Here is the output another output taken from Fraser_Bell’s response.

# update-alternatives --config default-displaymanager
There are 4 choices for the alternative default-displaymanager (providing /usr/lib/X11/displaymanagers/default-displaymanager).

  Selection    Path                                  Priority   Status
------------------------------------------------------------
* 0            /usr/lib/X11/displaymanagers/sddm      25        auto mode
  1            /usr/lib/X11/displaymanagers/console   5         manual mode
  2            /usr/lib/X11/displaymanagers/lightdm   15        manual mode
  3            /usr/lib/X11/displaymanagers/sddm      25        manual mode
  4            /usr/lib/X11/displaymanagers/xdm       10        manual mode

Press <enter> to keep the current choice
[li], or type selection number:[/li]```


sddm has a 
[*]mark before the 0 and my guess it is the one I am presently using.
13

Hmmnn, I recall after adding the line, I did a mkinitrd, before I rebooted my machine, that may be the trick that helped in changing my displaymanager to sddm.
I did it because every time I blacklist nouveau in /etc, I run mkinitrd all the time to make it work, before I can use the nvidia proprietary driver.

14

FYI there is a yast module for update-alternatives for those of us who don’t remember all command line switches or prefer using a mouse under a gui app it’s called yast2-alternatives I’m not sure if it’s installed by default as I haven’t had a need to change anything with it
https://software.opensuse.org/package/yast2-alternatives

15

FYI - Once you install the alternatives package, you’ll find it under the Miscellaneous tab in Yast.

16

And ‘yast2 alternatives will’ open it from any cmdline.

17

Thanks for that.

I hope they will ad that to the default installation in the future.
There is much more chance that users will learn about the existance of updatealternatives and it’s possibilties when they venture through YaST then when they have to stumble into a post here that explains it. updatealternatives it not an obvious feature for most and will get more exposure when supported through YaST.

18

Yes, I think that would be a sensible idea to include it by default. Just to note though, that it is mentioned in the release notes, and that’s what prompted me to install it soon after upgrading to Leap 15.

19

I installed Yast alternatives. But, in practice, I find that I am preferring to use the command line for switching alternatives.


cd /etc/alternatives
update-alternatives --config default-dis*
 ## select a value

The “cd” is only so I can use the “*” and avoid having to type in the full name.

20

It is not abut personal preference on how to do it. It is about spreading the knowledge of the existence and functionality of updatealternatives amongst the mass of our users.

When a user is a bit curious he will look through YaST to learn about it’s possibilities and thus the chance that e.g. when he wants to change his DM, he thinks: Oh, but I remember … wasn’t there something in YaST?
Look at the different threads since configuring which DM to use, is moved. Not only few people know it is moved, but then they wonder what updatealternatives is. And then they wonder why the step backwards, not being able to do this with YaST as before.