GRUB triple boot doesn't show other Linux

Hi there, I’m having a problem with GRUB where I’m trying to triple boot Windows, Fedora and Arch on one laptop. I shrank the windows partition, then installed fedora, then Arch, each with a partition layout similar to the fedora automatic partitioning. I’ve had no problems booting into either Fedora or Windows, but I can’t boot into Arch - even after running
grub2-mkconfig -o /etc/grub{,-efi}.cfg.
os-prober recognises that I have Arch Linux on my system, however when I reboot there’s no entry for arch.
I haven’t installed GRUB on arch as I want to use 1 grub config to manage all my OSes. I could create a manual entry in a custom file for grub, but if I do that, what would the implications of that be for using Secure Boot, as I know of only Ubuntu and Fedora having Secure Boot signed keys.

fedora’s grub/os-prober isn’t compatible with Arch. Arch uses multiple initrd images which Fedora’s grub/os-prober doesn’t support. Arch’s grub/os-prober supports both so you should either use that grub or add a manual entry for Arch. Make sure you add an initrd line for you ucode if you go that route.

As for secure boot, if it is a standard Arch install you will need to disable secure boot. I don’t think using Fedora’s grub will allow you to boot an unsigned kernel.

At one time I dual booted Fedora and Manjaro. Long, tedious story short: I got both to boot from the same grub menu after installing Manjaro first and going with Fedora’s grub. Manjaro menu blocks had to be copy/pasted from grub.cfg to Fedora’s. It worked well for a while and Manjaro menu entries stayed intact whenever Fedora installed a new kernel and rebuilt grub.

Eventually something went kaput and I decided dual booting Fedora with anything Arch-based was too high maintenance.

In your case be prepared for double trouble having two Linux installations on the same drive as Windows. Eventually Windows Update will overwrite the EFI partition and neither distro will have a way to boot.

Sorry for the late reply lol

Do you think it would be feasible for me to use dracut instead of mkinitcpio for initial ramdisk generation so that I only have one image GRUB needs to load?

If you mean on Arch, then probably but I have never tried it. If it works and the Fedora grub/os-prober can properly detect it, let us know. :smile: