On 03/09/2022 at 06:32, Philip Hands wrote:
Ansgar <ansgar@debian.org> writes:Source: rescue Version: 1.85 Severity: important I've installed a system using btrfs for the root filesystem with d-i (with disk encryption as well). As grub wasn't properly installed (not registered with EFI), I tried to use the rescue mode to reinstall grub. However, mounting the root filesystem failed: /target contained only a "@rootfs" subdirectory. So running a shell in the target fs failed. Manually mounting the filesystem with `-o subvol=@rootfs` worked. This was with Debian 11.4.
I just pushed 1.88 including this MR: https://salsa.debian.org/installer-team/rescue/-/merge_requests/1 which seems like it ought to address the problem you're experiencing.
If I understand correctly, the problem is in mounting a btrfs root filesystem. However the change in rescue 1.88 addresses only mounting extra filesystems such as /boot/efi or separate /usr.
I guess that handling btrfs subvolumes or other root filesystem mount options would require changes in the root file system selection step. I do not see how it could be automated (rootflags are defined in the boot loader configuration which may be located anywhere).