Arch Linux

piel

Member

Registered: 2012-01-20

Posts: 6

newly installed Arch on ext4 FS not recognized by other GRUB2 version

I have on old PC with BIOS. Two HDs one with Win98(yiykes) the other with MX Linux, Debian and Arch on diff partitions. Grub is installed by MX on the second HD MBR and i can boot all OS-es even Arch before I reinstalled it.

I broke pacman and libc so I decided to reinstall Arch from recent media (it is command line only). After i ran mkfs.ext4 and installed the rest, GRUB would not recognize the root file system of arch. Everything else works of course.
I booted MX and i could mount the Arch root fs and all was well. fsck said get a new fsck because FEATURE_C12 is present. It seems to be that my problem is that fstools are too recent.
I  tried installing grub on the partition and chainload as i do with the debian system but it did not work.

Now i see two ways around this but i don't want any of them and am unsure if they would work.
-Using the latest grub from the arch install would probably work?! bit i want to keep the one i have.
-wipe the root fs and use mkfs from MX but then i have to reinstall arch again, or use ext3

Is there a way to fix this issue without reinstalling Arch again? Turning off these new features for example , i would prefer.

thx

piel

hal8000

Member

Registered: 2011-05-20

Posts: 46

Re: newly installed Arch on ext4 FS not recognized by other GRUB2 version

Its a late reply but you can get out of this without re-installing.
You must know the root partition of Arch and you must either have
a live USB or Cd of Arch Linux or Endeavour Linux.

Feature C12 is present on Ext4 on Arch, Endeavour (don't know about Manjaro).

If you boot from the Endeavour Live image, you can follow these instructions:

https://discovery.endeavouros.com/syste … t/2022/12/

If you boot from the Arch Live image, you can follow these instructions.

https://wiki.archlinux.org/title/Chroot

Once you have mounted the root file system and changed root into your
old system, reinstall grub2 as Arch supports the new C12 features, and
compatible with your other distros.

Forge

Member

From: Bristol, VA, USA, Terra, Sol

Registered: 2014-12-16

Posts: 4

Re: newly installed Arch on ext4 FS not recognized by other GRUB2 version

I'm sorry, but no, you are not going to be able to get around this without switching your grub provider or reinstalling arch on a "older" ext4 partition. I have run into this issue while working on an older Ubuntu server. To fix a boot failure, I needed to format up a spare disk and rsync the contents across. Ubuntu would not boot. The Ubuntu-provided version of GRUB could not recognize the ext4 partition at all. It told me unrecognized filesystem. While hal8000's method would work fine for getting *into* the existing Arch install from another running Linux, all other things being equal, it will not work in this case, because both MX and Ubuntu will see the Arch partition as corrupt or unformatted. Mount attempts will fail because the Ubuntu/MX versions of mount will attempt a sanity-check fsck of the Arch ext4 partition, and it'll bail hard and fail the mount, because of unsupported features. The only "workaround" here that would work is using Arch's version of GRUB, which does understand the newer ext4 features, and you will still encounter problems trying to mount Arch's partition from MX or Ubuntu, until their e2fs-progs get to the same feature level as the Arch version that created the filesystem.

Sorry for the bad news, but I didn't want you hanging without a complete answer.

Strike0

Member

From: Germany

Registered: 2011-09-05

Posts: 1,487

Re: newly installed Arch on ext4 FS not recognized by other GRUB2 version

I have an install which uses a debian-11 grub install to dual-boot Arch. This works. See https://forums.debian.net/viewtopic.php?t=154055

Another simpler option (I have not tried) may be to remove the FEATURE_C12 of the Arch ext4 install for now, see https://github.com/NixOS/nixpkgs/issues … 1616324269

san2222

Member

Registered: 2023-07-03

Posts: 21

Re: newly installed Arch on ext4 FS not recognized by other GRUB2 version

So this must be the reason why My Mint's Grub can't recognize Arch. Please see my unanswered post here:

https://bbs.archlinux.org/viewtopic.php?id=287627

Thanks

san2222

Member

Registered: 2023-07-03

Posts: 21

Re: newly installed Arch on ext4 FS not recognized by other GRUB2 version

Doing

 tune2fs -l /dev/sda2 

on my Arch root drive gives this:

Filesystem volume name:   Arch
Last mounted on:          /media/san/Arch
Filesystem UUID:          1b5c60e4-42f9-42c8-9d1a-e346ca974b7f
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal ext_attr resize_inode dir_index FEATURE_C12 filetype extent 64bit flex_bg metadata_csum_seed sparse_super large_file huge_file dir_nlink extra_isize metadata_csum

As you can see FEATURE_C12 is enabled here. So yes, this might be whats causing GRUB to thrown "unknown filesystem errors".