do-release-upgrade from 23.04 to 23.10 leaves system unbootable

[Thomas Schweikle]

Install Ubuntu 23.04, then upgrade to the latest packages:

0. Select UEFI-Boot, deselect Secure-Boot in BIOS
1. Install Ubuntu 23.04 from ISO to root on zfs
2. apt update
3. apt upgrade
4. apt dist-upgrade
5. apt full-upgrade
6. apt autoremove
7. apt autoclean
8. reboot

9. install ubuntu-release-upgrader-core if it is not installed
10. remove all snapshots: zfs list -r -o name -t snapshot | xargs -n1 zfs destroy
11. do-release-upgrade --devel-release --allow-third-party
12. Wait ubuntu installing over 1400 packages, removing about 140 packages, doing some cleanup
13. reboot
14. Watch Ubuntu booting into UEFI menu
15. Have some analysis done.

Grub is missing from the just upgraded system.

ProblemType: Bug
DistroRelease: Ubuntu 23.04
Package: ubuntu-release-upgrader-core 1:23.04.7
ProcVersionSignature: Ubuntu 6.2.0-35.35-generic 6.2.16
Uname: Linux 6.2.0-35-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.26.1-0ubuntu2.1
Architecture: amd64
CasperMD5CheckResult: unknown
CrashDB: ubuntu
Date: Mon Oct 23 21:57:15 2023
InstallationDate: Installed on 2021-01-19 (1006 days ago)
InstallationMedia: Xubuntu 20.10 "Groovy Gorilla" - Release amd64 (20201022)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: No upgrade log present (probably fresh install)

[Thomas Schweikle (tps)]

Same for the now official upgrade. Regardless updating from commandline (do-release-upgrade) or via graphical application (update-manager). After having finished upgrading the system will boot into UEFI-Menu, not finding grub to boot.

The upgrade works, if the system is installed on ext4 with lvm. After upgrading the system will boot into Ubuntu 23.10.

The upgrade does not work, if the system is installed on zfs with root on zfs. After upgrading the system will boot into UEFI-Menu without any chance to ever start Ubuntu 23.10 -- grub is missing.

The upgrade does work partly, if the system uses an ext4 partition for boot, having /root on zfs. The system will boot into maintenance mode, unable to mount zfs-root. Looks like the modules for zfs are missing from the kernel.

The upgrade does work, even with zfs only systems if it is done from a booted life system.

[Thomas Schweikle (tps)]

Same while testing again.

23.04 -> 23.10: upgrade works until grub is upgraded and reinstalled.
Afterwards UEFI will not find and load grub any more. Failing to boot.

If grub is not replaced (it is enough to pin it to the old version), kernel 6.2.0 will stay bootable, while kernel 6.5.0 wont boot.

If removing outdated packages after installation as advised by do-release-upgrade you'll have an unbootable system afterwards. If pinning grub and kernel too what was installed by latest updates to 23.04 the system will stay bootable.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.