ugrading grub breaks ubuntu system boot (UEFI, BIOS), if root on zfs

[Thomas Schweikle]

Upgrading a root on zfs system will break this system. This is for:

- 22.04 -> 22.10
- 22.10 -> 23.04
- 23.04 -> 23.10
- 23.10 -> 24.04

- 22.04 -> 24.04

Workaround: set all grub packages on "hold" before upgrading.
If you do not, you'll lose booting possibilities, wrecking your system.

This is for UEFI-Booted system as for BIOS booted systems, as long as these are installed with root on zfs.

It is for UEFI-Booted systems regardless they are installed with root on zfs or llvm+ext4.

ProblemType: Bug
DistroRelease: Ubuntu 23.10
Package: grub-common 2.06-2ubuntu16
ProcVersionSignature: Ubuntu 6.5.0-27.28-generic 6.5.13
Uname: Linux 6.5.0-27-generic x86_64
NonfreeKernelModules: zfs
ApportVersion: 2.27.0-0ubuntu5
Architecture: amd64
CasperMD5CheckResult: unknown
Date: Thu Apr 18 13:58:22 2024
InstallationDate: Installed on 2021-01-19 (1185 days ago)
InstallationMedia: Xubuntu 20.10 "Groovy Gorilla" - Release amd64 (20201022)
SourcePackage: grub2
UpgradeStatus: No upgrade log present (probably fresh install)
mtime.conffile..etc.grub.d.40_custom: 2021-01-21T08:06:24.144234

[Mate Kukri (mkukri)]

Do you get any error messages with the boot failure?

[Thomas Schweikle (tps)]

Yes. Same message for Ubuntu or debian:

The UEFI loader does not find the file given. With VirtualBox I could read the message. With KVM it was impossible to read it. But it seems to be the very same message: failed to load Boot0001 "UEFI ....: not found"