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I'm on Ubuntu 18.04.1 LTS. I was running Nouveau and everything was fine, but in order to run Android Studio and emulate an Android device, I needed to install the Nvidia driver. I used the Software & Updates -> Additional Drivers, selected the NVIDIA driver metapackage from nvidia-driver-390 (proprietary, tested) and applied the changes.

The driver works fine but it enforces a maximum resolution that is lower than what I use with Nouveau, so I decided to switch back after finishing with Android Studio.

I switched back to Nouveau using the same Software & Updates -> Additional Drivers process. Now when I boot, my machine hangs and never reaches the sign in screen.

TL;DR

  • Nouveau was working fine.
  • Switched to Nvidia using the Software & Updates GUI.
  • Used for a few days (including reboot/shutdown).
  • Switched back to Nouveau using the same GUI.
  • Boot now hangs and doesn't reach the sign in screen.

Errors at startup

[FAILED] Failed to start User Manager for UID 121.
See 'systemctl status user@121.service' for details.
[  OK  ] Removed slice User Slice of gdm.
[  OK  ] Created slice User Slice of gdm.
... (repeated messages)
[  OK  ] Started Session c15 of user gdm.
[  OK  ] Removed slice User Slice of gdm.
[  OK  ] Created slice User Slice of gdm.
[FAILED] Failed to start User Manager for UID 121.
See 'systemctl status user@121.service' for details.
... (repeated messages)

$ systemctl status user@121.service
* user@121.service - User Manager for UID 121
 Loaded: loaded (/lib/systemd/system/user@.service; static; vendor preset: enabled)
 Drop-In: /lib/systemd/system/user@.service.d
          |-timeout.conf
 Active: inactive (dead)

Current workaround (after multiple attempts)

  • I boot by using nomodeset as per here.
  • Switch to Nvidia using the Software & Updates GUI.
  • Reboot to default Ubuntu install (works fine).
  • Switch to Nouveau using the Software & Updates GUI.
  • Reboot to default Ubuntu install (works fine).
  • Change resolution with xrandr.
  • Works until I do a full shutdown/startup.

I've seen solutions elsewhere, but they're either outdated or don't work. Can anyone advise how I can switch back to Nouveau without these problems?

Edit 1

I've tried adding nomodeset as per here.

  • I can get into Ubuntu.
  • Screen resolution is very low.
  • Can't change resolution as per here because xrandr: Failed to get size of gamma for output default.
Tom
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  • Have you tried with nomodeset while booting? – PRATAP Sep 18 '18 at 10:25
  • Thank you for your suggestion. I have not tried this. I'm relatively new to Ubuntu/Linux as a desktop - could you give me a bit more detail on how to try this? – Tom Sep 18 '18 at 11:28
  • please go through this Q&A https://askubuntu.com/a/1075682/739431 – PRATAP Sep 18 '18 at 11:29
  • Thanks for your help @PRATAP. I can get into Ubuntu but the resolution is far too low. See my question edit. – Tom Sep 20 '18 at 08:58
  • ya, nomodeset will give a chance to at least enter into Ubuntu. you need to install the rite drivers for your graphics card. or try to uninstall all the previously installed drivers and see. – PRATAP Sep 20 '18 at 09:03
  • The nouveau driver works fine, when I can boot into Ubuntu. The problem started happening after switching from Nvidia back to nouveau. So I feel the problem is where the Nvidia install has messed up some configuration files somewhere... but I don't know where. – Tom Sep 20 '18 at 09:27
  • When you switched from Nvidia to nouveau have you Uninstalled Nvidia drivers? – PRATAP Sep 20 '18 at 09:29
  • I used the Software & Updates GUI to switch from Nvidia to nouveau, so I don't know. I suspect that the Nvidia driver is still installed, but not used. – Tom Sep 20 '18 at 09:43
  • What is your graphic card model? – PRATAP Sep 20 '18 at 09:55
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    https://askubuntu.com/a/206289/739431 please go through this answer. – PRATAP Sep 20 '18 at 10:24
  • The card is GeForce GTX 750 Ti. Thanks for your suggestion. I followed that answer and was able to boot without problems this morning. I will wait for a few days to make sure it is working! :) – Tom Sep 21 '18 at 08:22
  • good idea @Tom. – PRATAP Sep 21 '18 at 08:39

0 Answers0