Switch from SDDM login to Plasma failed. No boot

Ask Fedora
1

Hi, I’m relatively new to Linux. Yesterday I attempted to revert my login manager back from SDDM to Plasma Login Manager. It resulted in this. Image attached of all i get from boot process. It appears to be loading the OS and in a later stage it switches from the normal Fedora loading spinner and logo to what you see in the image. But that’s it. Stops right there every time. There is a very slow cursor (not seen in the photo) that has a blink transition of about 10 seconds. But if I leave it nothing happens. Eventually I think the computer either turns off or goes to sleep. I can’t tell.

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I can boot into my windows partition and a Live Fedora kde USB environment just fine.

I attempted to use AI to help me resolve this via Konsol on Live USB. Confirmed my attempt to revert did remove SDDM and installed the plasma login manager as it said it had “nothing to do”. But this didn’t effect anything. The AI got into a loop of trying to get chroot to work. I think it kept using the wrong directory. My hunch. Either way it had no effect apart from wasting my time.

I would really like to not start again if I have to. I slept on it and just got up to start fresh. But I have no clue where to go apart from reformatting. Any assistance would be greatly appreciated. Thanks.

2

If you hit Ctrl+Alt+F3 do you get dropping into a new tty with login: prompt?

3

At boot. I tried it and I ended up in Grub2 kernel list.

4

I forgot to mansion that I tried the oldest Kernel in my list with no change.

5

And rescue just states it is locked. I don’t seem to have the option to offer-up a password.

6

Reinstating SDDM had no effect.

7

You’ve mention switching back to Plasma Login Manger from SDDM, and according to the log you posted, it’s started gdm.service - Gnome display manager.

As far as I know you should only have one of these enabled. It seems you’re using KDE/Plasma so gnome display manager isn’t needed.

And to confirm you disable and enabled the relevant systemd services?

sudo systemctl disable sddm
sudo systemctl enable plasmalogin

Also I believe you can disable gdm too.

8

Well according to what i was doing with the ai konsol showed SDDM not installed and plasma in place. Sorry I can’t be clear because all these weird names have confused me. i don’t know what is what any more. I need to get back to work so I have reformatted and starting over. Will reinstall user from backup. Linux has been a pain in the ars so far. I love it except it breaks a lot. Sick of Apple’s crap and don’t want to use windows more than forced to. I’ll get through it. I just have to close this so I can get back to work. I only have myself to blame. Thanks for chiming in.

9

If you enable a specific display manager the the other ones can’t be enabled at the same time. So for example

systemctl enable --force sddm

you will enable sddm and disable other display managers and

systemctl enable --force plasmalogin

will enable plasmalogin and disable the current display manager. Without sudo you will be asked for your password.

For historical reasons they are called “display manager”, but nowadays they are really login managers.

10

Indeed. I wouldn’t expect GDM to even exist on a normal Fedora KDE system!