Re: GRUB search doesn't set btrfs subvolume

[Andrei Borzenkov]

On 11.03.2023 00:14, Lyubomir Parvanov wrote:
> Hello,
> I have the following btrfs subvolumes on  my btrfs boot partition:
> sudo btrfs subvolume list /boot
> ID 256 gen 300 top level 5 path @boot
> ID 257 gen 301 top level 5 path @boot-snapshot
> ID 343 gen 285 top level 257 path @boot-snapshot/67/snapshot
> ID 344 gen 290 top level 257 path @boot-snapshot/68/snapshot
>
> When I try to boot I get into the Minimal Bash shell. Apparently the
> Kubuntu grub-mkconfig generates a grub.cfg which contains a call to the
> search command in order to set the prefix environment variable. But as far

And what is this search command?

Also show output of

lsblk -f

from your operating system where grub.cfg is generated.

> as I understand it doesn't take into account the btrfs subvolumes. The prefix
> environment variable has the value of (hd0,gpt2)/grub right after dropping
> into Minimal bash, and if i manually set the prefix to (hd0,gpt2)/@boot/grub
> instead and execute normal, the system boots successfully. What seems
> strange to me is that the calls to linux and initrd do in fact detect (and
> set) the @boot btrfs subvolume.

I do not understand what it means. What exactly "initrd detects and sets 
@boot" means?

> See this screenshot too: https://i.imgur.com/yd11WQ1.jpg
> I am also sending my grub.cfg file attached.
>
> I hope that you'll be able to help me find a solution to this issue.