Booting Multiple OSes Headaches

Hi all,

  1. I have EOS installed on an NVMe disk with EFI and no grub.
  2. Then I installed Windows 10 on a SATA disk, and it automatically used EOS’s EFI partition on the NVMe disk
    = EOS can see Windows if I boot EOS’ disk from BIOS
    = WIndows doesn’t see EOS if I boot it from BIOS
  3. Then I installed MX-Linux on a third (SSD) disk with its own EFI partition and grub
    = MX-Linux grub only sees Windows but not EOS. Os-prober and update-grub don’t find anything else.

So, how can I clean this mess and have EOS, which will fire up first in sequence from BIOS, see and boot BOTH Windows 10 and MX-Linux? EOS is my primary system.

(And is it normal for Windows to “steal” EOS’ EFI and lodge itself there?)

(And yes, I used rEFInd but I didn’t like it and removed it)

Thank you for the advice!

Change MX-LInux to use the same EFI partition as EOS & Windows and then you can easily chainload it.

Yes. Rather that steal, they are sharing.

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Thanks, dalto, that’s an interesting concept (and new to me).

Any pointer on how to have MX-Linux share that EFI partition on EOS?

But let’s say all three disks/systems are chainloaded to one EFI partition and that partition fails, won’t the other OSes become unavailable?

  • Boot into mx-linux.
  • Change /etc/fstab to use the other EFI partition
  • umount /boot/efi
  • mount /boot/efi
  • Call grub-install with appropriate options for mx-linux

Yes. Although, I don’t think EFI partitions fail regurlarly :slight_smile:

However, if you lost that entire disk, you would need to chroot into your remaining distro(s) and follow steps similar to the above.

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OK, that’s great, thanks for the steps.

Much appreciated! :+1:

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Hi again dalto, could you be more specific about changing fstab to use the other EFI partition? I’ve googled and, to be honest, I’m confused about how to do this… :slight_smile:

Do an lsblk -f from your MX installation to get the necessary UUIDs for your partitions (perhaps save the output to a text file), then look into the ArchWiki on fstab

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Thanks, Ivanhoe, will do that.