A small question off topic , I am asking here as I don’t find it necessary to create a topic for something this small.
Today when I booted Garuda gnome off of ventoy and went to clear my fat32 efi and btrfs partitions from my previous kde install , it showed that the btrfs root partition was mounted at var/lib/os-prober/mount
However since the first time , I have been unable to recreate a scenario where it was mounted automatically at that mount point . What does this signify and why was it automatically mounted ? I searched online and it seemed to be something related to grub and boot entries but am unable to find a proper explanation.
So after some searching and consulting grub’s manual , I have come to conclude that this whole issue was a bug or something like that from grub’s side as there is not enough details on how grub’s os-prober command works in detail .
To further support this fact , I am writing this reply off of ventoy in gnome garuda where in etc/default/grub os-prober was enabled by default and I had a garuda kde installation on my disk which got detected by os-prober as a valid os entry on boot as grub probably runs some command while loading up which in return runs this command . Therefore the root btrfs partition was mounted as an unexpected behaviour , also grub 2.0 hasn’t been updated since 2021 , this could further contribute to the issue .
Anyways I am now not bothered at all , as most of the issues were solved by the grace of sir @SGS , sir @Bro , sir @filo , sir @TilliDie and other forum members with their extraordinary fast assistance.
this reply also serves as a proof that I am not a help vampire.
I’m a little late to this thread, but here goes nothing:
Your conclusion is not quite right. There is no bug or unexpected behavior here. Let’s back up for a second:
Probably you had just run an update, and one of the packages updated was the kernel. In this case, a hook regenerates the Grub configuration file and os-prober will run if it is enabled.
That will regenerate the Grub configuration file, os-prober will run, and my guess is it will establish the mount you observed earlier.
This question is worded in a confusing way, but yes: os-prober is enabled by default in Garuda. This configuration choice deviates from the upstream default for Grub. The setting which specifically enables os-prober is this line in /etc/default/grub:
If you would like to disable it you can comment it out by placing a “#” at the start of the line, or just delete the line altogether.
I’m not sure where you read that, but that’s not right. Grub has been updated many times over the years–it tends to be a package which attracts a lot of attention when it is updated, because it does not always go smoothly.
Good for you, keep it up! It’s okay to ask questions and try to learn more, but hopefully you will get into the habit of first doing the research and trying to find the answers on your own.
On the first boot the Setup Assistant will run and do a full update. Any available package upgrade will be pulled down. Certain ones will initiate the regeneration of the Grub configuration file, such as an update to the kernel. When that happens, os-prober will run.
Installing Grub and generating the Grub configuration file is part of the installation routine, yes. Because os-prober is enabled in Garuda by default, it runs as part of that setup. The benefit of this is if you multiboot, when Grub comes up for the first time after a new installation, your other operating systems should show up in the menu.
Hmm, sort of? It is more related to Grub. Calamares kicks off the commands that install Grub, run os-prober, and generate the config file but none of that is specific to Calamares. That is just how we set it up for Garuda Linux.