Changing root is commonly done for performing system maintenance on systems where booting and/or logging in is no longer possible. Common examples are:

Then we mount the partitions we need and undo whatever broke your system.

Get yourself the latest Arch Linux ISO

or ArcoLinux

and keep it around

These commands will be used IF

loadkeys be-latin1

or you use setxbmap and the keyboard

setxkbmap be
mount /dev/sda3 /mnt
mount /dev/sda1 /mnt/boot/efi
arch-chroot /mnt

You can add swapon /dev/sda2 but I rarely do out of laziness and there is no issue.

Then you are in your actual computer – install, uninstall, change configs and repair your computer.

BIOS

These commands will be used IF

loadkeys be-latin1

or you use setxbmap and the language

setxkbmap be
mount /dev/sda1 /mnt
arch-chroot /mnt

You can add swapon /dev/sda2 but I rarely do out of laziness and there is no issue.

Then you are in your actual computer – install, uninstall, change configs and repair your computer.

WHAT IF …

If you did something completely different, you will need to analyze what are your partitions.

Use lsblk for that.

Let us analyze the following partitioning.

loadkeys be-latin1

or you use setxbmap and the keyboard

setxkbmap be
mount /dev/sda2 /mnt
mount /dev/sda1 /mnt/boot/efi
arch-chroot /mnt

You can add swapon /dev/sda3 but I rarely do out of laziness and there is no issue.

How to fix a kernel not booting or is it the grub?

PUT your data on an USB stick
or external harddisk

/boot/vmlinuz-linux can not be found

Solution : reinstall the kernel – update-grub

sudo su (no password if you use ArcoLinux ISO to become root)

Blinking cursor in the top left and black background

patient : ArcoLinuxB Plasma

We check all elements. Where can it can go wrong? In what phase of the boot process?

  • linux kernel – other kernels
  • amd-ucode or intel-ucode
  • grub
  • nvidia
  • rip in the terminal to see the last updates
  • what did you do?

You need to think back and analyze what can be the reason.

Here the solution was one simple line.

sudo systemctl enable sddm -f

That was the solution IN MY CASE. Lightdm is not working then we switch to sddm and wait for the updates.

It is all about trial and error.