Arch Linux

Noki

Member

Registered: 2018-06-08

Posts: 98

[SOLVED] os-prober and grub-mkconfig fail to find Arch

Hi All,

I managed to break Arch today, I had two EFI partitions and deleted one thinking it was useless. It was the only change I made so must be the cause. I have 4 OS and 3 of them still boot fine, only arch fails (it does nothing when selected in grub as if it's missing entirely.

I booted from a usb drive to fix it and I am stuck on a step. Since I am not reinstalling the whole OS I followed the wiki installation guide but skipped the unneeded steps. I have 4 OS's, Windows, Mint 20, Mint 20.1 and Arch. Each lives on the same SSD 'sdD' on partitions 4,5,6 and 7.

I started by mounting Arch root sdd7 to /mnt then used arch-chroot to switch to it. I then mounted the EFI partition to /boot (where it was before) and ran:

grub-install --target=x86_64-efi --efi-directory=boot --bootloader-id=GRUB

Followed by grub-mkconfig -o /boot/grub/grub.cfg and finally os-prober.

Both commands list Windows and the 2 Mint installs, but no Arch. I can see my /boot/ directory contains an arch folder with an EFI file which might be from an older install but I don't see why it would not find arch but still be able to find the others.

Am I missing something?

Happy to run any commands and post the output, any help appreciated.

https://wiki.archlinux.org/index.php/installation_guide
https://wiki.archlinux.org/index.php/GR … allation_2

Last edited by Noki (2021-03-16 01:13:27)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,728

Re: [SOLVED] os-prober and grub-mkconfig fail to find Arch

That's expected, os-prober is for identifying systems that are not the system grub is being installed on/for. Check/post the generated grub.cfg and maybe an

lsblk -f
sudo efibootmgr -uv

Last edited by V1del (2021-03-15 23:45:18)

Noki

Member

Registered: 2018-06-08

Posts: 98

Re: [SOLVED] os-prober and grub-mkconfig fail to find Arch

It's missing entirely from the grub.cfg that was generated. The output from those commands is here: https://imgur.com/EZhlKHX

The two 'arch' and arch again' entries are old and do not work. the ubuntu one was created using the ubuntu recovery util that usually works for me https://help.ubuntu.com/community/Boot-Repair

The grub one at the bottom was created just now by me attempting to fix, it is obviously missing arch but has the other 3.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,728

Re: [SOLVED] os-prober and grub-mkconfig fail to find Arch

And your vmlinuz and initramfs files are located where? On the EFI you've mounted to /boot or on the root's partitions /boot directory? If you do not mount the ESP what are the contents of /boot ? If these contain the vmlinuz images you need to either move them to the ESP or reinstall GRUB/at least the GRUB config into the /boot directory rather than the EFI mountpoint

Noki

Member

Registered: 2018-06-08

Posts: 98

Re: [SOLVED] os-prober and grub-mkconfig fail to find Arch

Ugh thanks that solved it. I was a directory too low, /boot/efi/ was correct. Can't see the wood for the trees sometimes!

Thanks again.