Arch Linux

finkrer

Member

Registered: 2020-05-13

Posts: 1

GRUB error: unknown filesystem

Hi everyone.

I've been using Arch for half a year now and it was working fine, but recently I've been having occasonal Grub errors on boot.
I've tried the usual ways of booting from the rescue mode, but it all comes down to the fact that it really can't recognize the filesystem.
It goes kind of like this:

error: unknown filesystem
Entering rescue mode...
grub rescue> ls (hd0,1)
(hd0,1): Filesystem is f2fs
grub rescue> ls (hd0,1)/
<this seems to give me random stuff from the disk, usually it's just blank, but I've had it dump a full page of minified JS on me once>
grub rescue> ls (hd0,1)/boot
(hd0,1): Filesystem is unknown

I haven't had any luck with the rescue shell, so I got myself a live CD to do stuff from there. At first I was running grub-mkconfig and it worked, but then I noticed it doesn't really change the config, so with some trial and error it turned out all I need to run to fix this is

mount /dev/sda1 /mnt

And when I reboot, there's no error.
But then a day or two later it's there again, and I have no idea what triggers it.

I do know what made it appear in the first place. As you may have noticed I'm using F2FS, and it was working just fine. However, mkinitcpio was complaining that I don't have fsck.f2fs installed, so I decided to fix that.
Then it turned out that fsck.f2fs does a check every time there is a new kernel, which is quite often. So I decided to remove the fsck hook and fsck.f2fs as well.
On reboot I got the error above.
When I managed to boot again, I put everything back in, but the error was still occurring from time to time.
Now I removed it again and added the fsck.mode=skip kernel parameter, since having fsck on didn't help anyway.

lsblk -f

NAME   FSTYPE FSVER LABEL UUID                                 FSAVAIL FSUSE% MOUNTPOINT
sda                                                                           
└─sda1 f2fs   1.13        4a964602-121b-44dc-80f8-b73bc5977ef4  138.3G    41% /

fdisk -l

Disk /dev/sda: 232.91 GiB, 250059350016 bytes, 488397168 sectors
Disk model: Samsung SSD 860 
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x5fc2cf7f

Device     Boot Start       End   Sectors   Size Id Type
/dev/sda1  *     2048 488397167 488395120 232.9G 83 Linux

lamyseba

Member

Registered: 2022-10-29

Posts: 2

Re: GRUB error: unknown filesystem

Hi, same problem here. Did you find out a solution ? Maybe having an ext4 /boot partition could help ?

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 76,446

Re: GRUB error: unknown filesystem

Don't install grub on a f2fs, https://wiki.archlinux.org/title/F2FS#GRUB_support

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lamyseba

Member

Registered: 2022-10-29

Posts: 2

Re: GRUB error: unknown filesystem

Thanks Seth for your answer. I'm running Manjaro where grub is installed by default. What alternative to grub do I have that work with f2fs, and does not require to much job each time a new kernel is published ?

Scimmia

Fellow

Registered: 2012-09-01

Posts: 13,729

Re: GRUB error: unknown filesystem

If you're on Manjaro, why are you here? When you registered, you specifically agreed to a screen that said Manjaro wasn't supported here.

And necrobumping to boot.

Last edited by Scimmia (2022-10-31 19:32:58)

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,654

Re: GRUB error: unknown filesystem

Using this opportunity to close this old thread.

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