grub-probe: error: compression algorithm inherit not supported

grub supports a limited set of zfs features and compression algorithms, it is up to you to setup /boot on a file system it supports.

Notably for zfs you need to create a bpool with the grub2 compatibility mode.

As there is no use at all for compression on the boot partition seeing as kernels and initrds are compressed already I'm going to close this Won't Fix.

What are you talking about this is just automatically generated partition made by guided installer it is not as if I did something to the bpool. You make it sound as if I modified bpool somehow. This partition layout is just generically generated by the installer !

The original generated grub by the installer works fine. Only when upgrading it gets fucked up. Clearly something is wrong.

Currently made dd backup of bpool and when ever grub fucks it up i write that image back too the partition and then it just works again.

What I currently changed in /etc/default/grub is GRUB_DISABLE_OS_PROBER=true

Since I changed that setting i don't see the error about inherit support anymore. Still need to test if it will boot now.

Vanilla 23.10 install a week ago. Multiple reboots over the week, no problem. Today it boots into grub cli interface.

Booted a live cd, mounted the zfs volumes, mounted /dev, /proc, /sys, /run into the new root, chrooted in.

   # grub-install /dev/nvme0n1
   Installing for x86_64-efi platform.
   grub-install: error: compression algorithm inherit not supported
   .

No special grub or zfs changes from the install, no `dd` games like ofloo, it's 100% vanilla.

@juliank I think needs another look, it seems that users' working boot ZFS volumes are becoming incompatible on the fly after some (possible unrelated to GRUB) update.

I have experienced this today on an Ubuntu 22.04 system. When I try to ls the bpool from the grub command line:

error: compression algorithm inherit not supported

The bpool is mirrored on 2 nvme partitions, same behaviour for both.

Now worried about restarting other servers which have a similar disk layout. I had an uptime of about a month and a pending reboot for a kernel upgrade. If I can rescue the system I can check apt logs to see what has been updated.

I redid my install with https://docs.zfsbootmenu.org/en/v2.3.x/guides/ubuntu/uefi.html

Now works fine. Boot from Live cd and follow the instructions need to mod the version to latest but that's about it. Then you just apt install the desktop.

I mean I'd rather see people fix their shit but from this conversation that doesn't seem to be happening soon. But that's the great thing about linux there's always a different path.

This is reported in openzfs#13873 and is apparently fixed with grub 2.12. The cause is apparently creating a top level snapshot in the bpool but I've had a cron job which has been doing that since installing the system. Perhaps the 2.2.0 zfs version in the 6.5 jammy hwe kernels is the contributing factor.

As a workaround I have replaced grubx64.efi on the ESP with the one extracted from Debian sid's grub-efi-amd64-bin_2.12-1_amd64.deb which has my system booting again. I tried with the proposed package from Ubuntu 24.04 first but that did not work.

It's been fixed, .. said to see that it's been fixed and that the fix hasn't been pushed downstream.

My opinion is that "Won't Fix" is not the correct action for this bug:

- it is an acknowledged issue in grub which is now resolved
- it is a regression in that previously functioning systems with a bpool configured according to guidelines stops working after upgrading to the latest Jammy HWE kernel when a pool level snapshot is created
- my failed attempt to workaround the problem using the package from 24.04 suggests that the forthcoming LTS release could be susceptible to this problem

Related links:
- https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/2041739
- https://ubuntuforums.org/showthread.php?t=2494397&p=14175278
- https://savannah.gnu.org/bugs/index.php?64297 (bug still open, perhaps fixed without referencing it?)

Maybe 24.04 package has been updated now, as I extracted grubx64.efi from the current noble deb file and replaced my local version, and now I can boot again.

https://packages.ubuntu.com/noble/grub-efi-amd64-bin