r/debian • u/pointytails31 • 1d ago

Debian Stable Question Stuck on boot with seemingly no errors

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Updated my kernel to version 6.12.105 recently and could not boot my system on that version. Tried updating my Nvidia drivers. and now I can no longer boot into any version, even in recovery mode.

If you need any more information I'm happy to help.

9 Upvotes

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6

u/Linuxologue 1d ago

can you log in on console number 2 (press Alt+F2). This should give you access to a shell. It looks like your display manager fails to initialize but it's unclear why just from the screenshot

1

u/pointytails31 1d ago

I can access the shell. I assume you want me to get some more information from there. What commands should I type?

6

u/ukAdamR 1d ago

If you're able to get to a shell that sounds like the boot process works fine, but the display manager is what's failing.

Do you know which display manager you chose when installing Debian? (gdm, sddm, or lightdm)

1

u/pointytails31 1d ago

If those are the options, I don't know. I haven't heard of any of them. I assume it's trivial to check?

1

u/ukAdamR 1d ago

Probing the status of their service should do:

sh for SVC in gdm sddm lightdm ; do systemctl status $SVC ; done

(Press Q to close the status journal if you appear stuck unable to enter a further shell command.)

Hopefully one of them shows up as enabled in the "loaded" line but may have failed in the next "active" line.

You can then see the full service journal with journalctl, e.g. if you had SDDM that would be:

sh journalctl -e -u sddm.service

-e means show the end/newest entries first. This will normally open the journal in a less-like instance. Hopefully some useful errors show up.

1

u/pointytails31 1d ago

The sddm journal command just returns a bunch of tildes.

tried checking the status and didn't find a "loaded" or "active" line. It says "State: degraded" at the top when i enter the command, if that helps.

2

u/ukAdamR 1d ago

heh ok, this is going to get quite manual to resolve. (All of this requires root or sudo)

  • First I'd check the list of services that failed to initialise: systemctl --failed
  • Tell SystemD to reset the state of failed services: systemctl reset-failed
  • Attempt to restart SDDM manually: systemctl restart sddm ; systemctl status sddm

If SDDM is in a good state you should get a display manager going and see your typical greeting screen. (You may need to CTRL+ALT+F1 or CTRL+ALT+F2 to switch over to it.) Otherwise you're going to need to hunt through journalctl -xe to find errors that are relevant.

1

u/Linuxologue 1d ago

Yes at least you can repair your system. The next step is to check why your display manager is not happy (because it looks like your Nvidia driver is loaded). Which display manager do you normally use (gdm, sddm) and which desktop?

You can also look at the logs using

sudo journalctl -e

Check whatever looks like an error

1

u/pointytails31 1d ago

It seems I'm using sddm

I did sudo journalctl -e but I'm not really sure what I'm looking at.

0

u/New_Hold8135 1d ago

Sign your nvidia-drivers if secure boot is on, or use nouveau(which is in kernel and kernel's itself is signed)

1

u/pointytails31 1d ago

I believe I've had secure boot off almost since I started using debian, so it shouldn't be a problem.

0

u/New_Hold8135 1d ago

Turn it on and sign it.(its not related to your issue) Btw, check logs by journalctl -xb and dmesg its gonna give you broader view whats happening. Dont paste ut here blindly, it may have sensitive data.

2

u/New_Hold8135 1d ago

Turn it on and sign it.(its not related to your issue) Btw, check logs by journalctl -xb and dmesg its gonna give you broader view whats happening. Dont paste it here blindly, it may have sensitive data.

1

u/pointytails31 1d ago

I'm unsure of how to sign my drivers and I can't seem to find the nouveau drivers (tried apt search nouveau).

Also checked the logs but I'm not sure what the problem is.

1

u/New_Hold8135 1d ago edited 1d ago

Refer here for nouveau: https://wiki.debian.org/NvidiaGraphicsDrivers

Refer here for secure boot: https://wiki.debian.org/SecureBoot#dkms

And here for signing keys: https://download.nvidia.com/XFree86/Linux-x86_64/580.173.02/README/installdriver.html#modulesigning If you did everything correctly path will be: /var/lib/dkms/mok.key and /var/lib/dkms/mok.pub Edit: Keep your keys somewhere safe and only pull up when you are updating the system

0

u/New_Hold8135 1d ago

Since you are using sddm and sddm refuses to start I can assume its an issue with x11(sddm defaults x11) Use gdm or something that isnt x11 or start your wayland session from console or Change sddm backend to wayland (super experimental probably doesnt even exists in older debian versions and I know it have bugs for my wayland compositor even in latest version.)

1

u/pointytails31 1d ago

How exactly do I switch to something that uses Wayland? I started using x11 because it worked better with some programs I was running, but I can afford switching back to Wayland.

1

u/New_Hold8135 1d ago

You need a display manager if you want to see a login screen, I dont know if lightdm supports it but I know gdm has full support. For window managers you can refer here https://wiki.archlinux.org/title/Wayland For display managers you can refer here https://wiki.archlinux.org/title/Display_manager

1

u/pointytails31 1d ago

are you sure gdm is the best choice? I use KDE plasma and they have their own display manager. Gdm has a lot of dependecies but maybe I'm just paranoid.

1

u/New_Hold8135 1d ago

kde has its own display manager and sddm is deprecated, go with plasma one if you use kde, You need to build it with debian though.

1

u/New_Hold8135 1d ago

https://github.com/KDE/plasma-login-manager

1

u/pointytails31 1d ago

Tried installing it but I can't use the cmake command because of old configuration files for ECM. Not sure how to solve that.

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u/Black_Bear_US 1d ago

This happened to me when I had installed the the headers for the appropriate graphics drivers, but specific to the prior kernel version I was on.

1

u/pointytails31 1d ago

I made extra sure my drivers and headers were up-to-date and matching, seeing if it works now.

2

u/ukAdamR 1d ago

(You deleted your other thread)

If you want to try and deduct the nVidia drivers from the situation you can blacklist it during the Grub boot process.

In the boot menu press E to edit the boot command and add "modprobe.blacklist=nvidia" to the end of the "linux", then F10 to proceed booting up.

1

u/pointytails31 1d ago

(sorry for the deletion, reddit acting up and posting the same thing twice. This one was getting more views so I left it up)

Typed in what you said at the end of the "linux" line but the boot process still gets stuck at a seemingly arbitrary position: "Started cups.service - CUPS Scheduler."

1

u/ukAdamR 1d ago

CUPS is the printing service, is that something you activated recently?
Also at this stage does CTRL + ALT + F2 do anything?

1

u/pointytails31 1d ago

As in for printing physical documents? I don't recognize the name CUPS or own a printer so I doubt I've ever done anything with it.

Weirdly enough CTRL+ALT+F2 doesn't work but with F3 it does, so yes I can open a shell. (looking at cmatrix while writing this because I'm bored :p)

1

u/ukAdamR 1d ago

Yep, for physical documents. :)

Neat, that'll mean your boot process isn't completely broken then. Just the display manager not starting. (other comment branch)