[Dragora-users] (bug) failed to install grub with ext4 root partition

[Jing Luo]

Hi all,

TL;DR: Dragora 3.0 beta 2 ships with GRUB 2.06 that fails to recognize 
ext4 root partition, it should be upgraded to 2.12.

I tried to install Dragora on a qemu VM. I used the whole disk for the 
root partition, with MBR and bootable flag. Then I formatted the root 
partition as ext4 like I always do. Then grub-install failed.

grub-install: error: unknown filesystem

I believe this is the exact bug reported here [1].

[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=866603

If I follow the workaround in [2] to disable an ext4 feature 
"metadata_csum_seed", yes, grub-install would succeed, but only grub 
could only be installed on MBR, not superblock:

# (after bind mount and chroot)
# grub-install --taget=i386-pc --boot-directory=/boot 
--directory=/usr/lib/grub/i386-pc /dev/sda1
grub-install: warning: File system ext2 doesn't support embedding.
grub-install: warning: Embedding is not possible. GRUB can only be 
installed in this setup by using blocklists. However, blocklists are 
UNRELIABLE and their use is discouraged..
grub-install: error: will not proceed with blocklists.

After installing grub to MBR, unfortunately after reboot, there was a 
"kernel panic - not syncing: VFS: unable to mount root fs on 
unknown-block(0,0)". If I re-enable "metadata_csum_seed", then grub 
couldn't boot (unknown filesystem).

[2] 
https://www.linuxquestions.org/questions/slackware-14/grub-related-issue-with-alienbob%27s-current-64-bit-isos-clean-fresh-install-4175722697/#post6417052

This is so unfortunate I ended up with a broken install :( But there 
seems to be a patch [3] that can solve this. Or better: upgrade GRUB to 
2.12 where the patch was merged.

[3] 
https://git.savannah.gnu.org/cgit/grub.git/patch/?id=7fd5feff97c4b1f446f8fcf6d37aca0c64e7c763

--
Jing Luo
About me: https://jing.rocks/about/
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