I have installed Ubuntu 18.04 on my Dell XPS 15 laptop. I was working fine until yesterday. After a system update, I cannot log in to Ubuntu using normal mode. This is the error I am getting:

Gave up waiting for root file system device. Common problems:

-Boot args (cat /proc/cmdline) - Check rootdelay=(did the system wait long enough?) -Missing modules (cat /proc/modules; ls /dev) ALERT! UUID=22f93100-9860-44b7-8086-51b4404d499d does not exist. Dropping to a shell

BusyBox v1.27 2 (Ubuntu 1:1.27.2-2ubuntu3) built in shell (ash) Enter 'help' for a list of built-in commands.


Ubuntu is opening in recovery mode. But there I cannot change the display brightness. In fact,when I did this to check the driver: ls /system/class/backlight

I found none.

Is there any way I can recover Ubuntu without reinstalling? I have many software's installed and I don't want to loose them now.

Thank you, Arka

  • Try sudo update-grub – Vijay Dec 10 '18 at 16:24

Check if you have cryptsetup installed on your system, it might have been removed by running apt-get autoremove. More info.

  • 1
    Actually that was it for me! Thanks!!! :) – Willi Mentzel Jun 23 '20 at 19:49

if you see "ALERT! UUID=22f93100-9860-44b7-8086-51b4404d499d does not exist. Dropping to a shell"

and you are not aware of wrong disc definition - you might be fooled by GRUB.

Interrupt GRUB when offering the choices. So

when the GRUB boot options appear do press e for edit.

Check everything properly.

In my case (migrated image):

There you may first find perfectly right entries like UUID=[here-comes-your-accurate-value]. And further down an entry like root=UUID=some-weird-stuff-comes-here.

This is the fuckup in my case: a wrong root partition definition by GRUB.

You may just enter the proper value as simple /dev/sda1 or /dev/nvme2p3p4pblablabla notation instead of complicated UUID.

(UUID can be found by typing in CLI:

ls -latr /dev/disk/by-uuid/

which can be done with a DVD/stick external boot beforehand).

Of course there are issues with sda and hda and differernt numbering every time you boot (modern times are soooo cooool :-( ) and complicated partitions may use a different root setup. But you have to start somewhere ....

Works 4 me ;-)

When you booted successfully fix the underlying issue in grub config.

My opinion: While Lilo ws straight GRUB is back-stabbing.

  • Worked with Linux Mint 19.3 xfce 32 bit – NicolasSmith Jan 20 '20 at 20:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.