Arch Linux

joram200

Member

Registered: 2026-03-30

Posts: 1

error kern fs c grub_fs_probe 122 unknown filesystem

Ever since I had reallocated an exFAT partition to my windows partition my grub doesn't function normal. When entering lsblk, the boot partition is mounted in the correct location:

NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
zram0       253:0    0   7.7G  0 disk [SWAP]
nvme0n1     259:0    0 953.9G  0 disk 
|-nvme0n1p1 259:1    0   260M  0 part 
|-nvme0n1p2 259:2    0    16M  0 part 
|-nvme0n1p3 259:3    0 751.6G  0 part 
|-nvme0n1p4 259:4    0     1G  0 part /boot
|-nvme0n1p5 259:5    0   199G  0 part /
`-nvme0n1p6 259:6    0     2G  0 part 

What should I do?

frostschutz

Member

Registered: 2013-11-15

Posts: 1,639

Re: error kern fs c grub_fs_probe 122 unknown filesystem

Did you reinstall Grub? (sometimes it's just a necessary module missing in grub efi or core image, or changed device name, UUID)

Can you reproduce the issue with grub-mount? Sometimes Grub stumbles over new / unusual filesystem flags, or there's a bug in Grub's filesystem driver, there was an issue like that last year but it got fixed... old thread https://bbs.archlinux.org/viewtopic.php?id=303725 (hmmm there was a bugtracker discussion too, can't find it atm)

oh, here it is https://gitlab.archlinux.org/archlinux/ … k_items/12 (maybe you can use similar steps to debug what's going on in grub, if you get to a grub shell anyways - only if the reinstall doesn't help)

Last edited by frostschutz (2026-03-30 07:24:10)