Adding other distro to GRUB does not works

General system Kernel, boot, graphics & hardware
1

Hey guys,

I know that I am missing something, but I would love to count with your help if possible.

I have two 1 TB SSDs here, and I have EOS in one of them. I installed other distro (Debian) on the other one, and now I can perfectly boot the two distros.

But I need to enter that “boot menu” from my laptop (ACER = F12) in order to select what disk I want to boot on.

I was trying to update my GRUB in order to have all distros on perfectly acessible when I boot the machine, but I don’t get to make it works.

I ran os-prober but it has no output. Also, running grub-mkconfig -o /boot/grub/grub.cfg on EOS does not adds Debian entries to my boot menu.

I have already mounted the two devices on which Debian is (from EOS), before to run all the above, without success.

My disks currently are as follows (both are using Btrfs filesystem):

NAME        MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINTS
sda           8:0    0 894,3G  0 disk  
├─sda1        8:1    0 893,3G  0 part  
└─sda2        8:2    0  1000M  0 part  
nvme0n1     259:0    0 931,5G  0 disk  
├─nvme0n1p1 259:1    0     1G  0 part  /boot
└─nvme0n1p2 259:2    0 930,5G  0 part  
  └─root    254:0    0 930,5G  0 crypt /var/log
                                       /home
                                       /var/cache/pacman/pkg

/dev/sda is the SSD on which Debian is.

/dev/nvme0n1 is the SSD on which EOS is.

So, I would really appreciate any help if possible.

2

Edit /etc/default/grub and set DISABLE_OS_PROBER=false
Run sudo grub-mkconfig -o /boot/grub/grub.cfg

I’ve never had top update grub manually on Endeavour so that’s a (educated) guess.

3

Thank you very much.

I forgot to mention, but I have already set DISABLE_OS_PROBER=false. And even so that is not working.

4

Is os-prober installed?

Run yay -S os-prober to install it. It’s not installed on my system but I’m using systemd-boot so that may be a red herring.

5

Yes, it’s installed.

I don’t know why that is not working.

6

I believe os-prober has some issues with finding installed OS’s on BTRFS filesystems due to the way it functions

Perhaps try os-prober-btrfs from the AUR, which is a modified version of the tool for handling BTRFS specifically

I believe you also need to make sure you do this on whichever drive is first in your machine’s boot order, as you currently have a separate installation of grub on each drive and updating the one for whichever OS you have booted at the time will only update the install on that particular drive - IE, if you were to update grub.cfg correctly while running the OS installed on /dev/sda, but the drive at /dev/nvme0n1 is first in the boot order, you would never see that it has worked unless you manually selected to boot from /dev/sda because the grub instance on /dev/nvme0n1 remains unchanged.

(Personally, I prefer not unifying my grub at all if I’m using a system with only one OS per drive - I much prefer using the BIOS/UEFI boot device menu to select it, that way you eliminate a lot of complexity in bootloaders and also sidestep any potential issues where something that knocks out your bootloader leaves you with no bootable OS at all instead of just the OS you were playing with at the time :smile: )

3 Likes
7

Hey @z580c ,

Thank you so much. I did not know os-prober-btrfs, and it worked very well! Everything is working fine now.

After running os-prober I just ran sudo grub-mkconfig -o /boot/grub/grub.cf and this time Debian was detected.

Well, now I have already done the procedure. :smiley:

I read what you said regarding BIOS/UEFI but, unfortunately or not, now I did that. :frowning:

Anyway, many thanks for all your support, guys.

1 Like
8

Exactly!

9

Yeah, sometimes it seems nice to put all your eggs in one basket, till you break one and they all get mucky. Part of me still wants to boot everything from one place, but using the UEFI bios as the selector (either via del key on boot or efibootmgr) keeps things more effectively isolated.
Frustratingly as it seems, Rick is probably right if you (me) insist on more than one distro per PC.

10

I like to use one bootloader for all if I’m using grub but it has to be the distro that works. On some distros grub doesn’t play nice with others. So i let the distro that works properly control the boot of the others. I don’t like to get into custom grub configurations in order to boot others. To much messing around just ends up with a bigger mess! :rofl:

11

Hey guys,

Thank you all for all the help and advices. :slight_smile:

I finally decided: I’ll choose the distro / disk I will boot through F12, without messing with GRUB, etc. That is really very complicated and subject to “failures”.

Well, pressing F12 each time I want to boot the other distro is not that complicaded. :smiley:

1 Like