Root filesystem isn't btrfs

[Git-Forked]

Adding boot menu entry for UEFI Firmware Settings ... Root filesystem isn't btrfs If you think an error has occurred, please file a bug report at "https://github.com/Antynea/grub-btrfs"

[kevinchevreuil]

What is the return of the lsblk -f command?

[rapenne-s]

I have the same error, I'm using a root btrfs made of two LUKS partitions

# lsblk -f
NAME                                          FSTYPE      FSVER LABEL UUID                                 FSAVAIL FSUSE% MOUNTPOINTS
sda                                                                                                                       
└─sda1                                        crypto_LUKS 2           1815e7a4-532f-4a6d-a5c6-370797ef2450                
  └─luks-1815e7a4-532f-4a6d-a5c6-370797ef2450 btrfs                   55321929-7e31-4bcc-8057-5a2f0aff40e4   61,3G    91% /nix
                                                                                                                          /home
                                                                                                                          /
sdb                                                                                                                       
zram0                                                                                                                     [SWAP]
zram1                                                                                                                     
zram2                                                                                                                     
nvme0n1                                                                                                                   
├─nvme0n1p1                                   crypto_LUKS 2           24682f88-9115-4a8d-81fb-a03ec61d870b                
│ └─luks-24682f88-9115-4a8d-81fb-a03ec61d870b btrfs                   55321929-7e31-4bcc-8057-5a2f0aff40e4                
└─nvme0n1p2                                   vfat        FAT32 boot  7C0B-2F4C                             213,8M    58% /boot

[kevinchevreuil]

Hello @rapenne-s,

Why the /nix, /home and the / shares the same mountpoint?

[rapenne-s]

Hi, they are all different subvolumes in the same btrfs filesystem.

[rapenne-s]

this should be easier to get the picture of the mountpoints

/dev/mapper/luks-1815e7a4-532f-4a6d-a5c6-370797ef2450 on / type btrfs (rw,noatime,compress=zstd:3,ssd,space_cache,subvolid=15361,subvol=/gentoo)
/dev/mapper/luks-1815e7a4-532f-4a6d-a5c6-370797ef2450 on /home type btrfs (rw,noatime,compress=zstd:3,ssd,space_cache,subvolid=264,subvol=/home)
/dev/mapper/luks-1815e7a4-532f-4a6d-a5c6-370797ef2450 on /nix type btrfs (rw,noatime,compress=zstd:3,ssd,space_cache,subvolid=263,subvol=/nix)

but /dev/mapper/luks-1815e7a4-532f-4a6d-a5c6-370797ef2450 needs /dev/nvme0n1p1 and /dev/sda1 to work, as the FS is spread across the two partitions.

[rapenne-s]

grub-probe doesn't work at all with my setup, and it has bugs with FS on multiple drives (which I experienced):

• https://savannah.gnu.org/bugs/?48228
• https://savannah.gnu.org/bugs/?54575

it's more likely to be a grub problem than a grub-btrfs problem.

[Schievel1]

Jup, looks like it. I also have the same problem now. See https://github.com/Antynea/grub-btrfs/issues/266#issuecomment-1484159140

I will use something different to detect the root fs in the future.