Installed today's (April 22 2024) I presume last beta for ubuntu 24.04 using the desktop livecd and the instructions for root install.

[Phoenixxl]

Today - since -31 came bundled with the latest daily version for the 24.04 beta - I decided to follow the instructions for the 22.04 install found here:

https://openzfs.github.io/openzfs-docs/Getting%20Started/Ubuntu/Ubuntu%2022.04%20Root%20on%20ZFS.html

Since zfs can't be installed natively from the 24.04 server install cd using subiquity this page will become very relevant again during the following days.

Following the howto by the letter for a single disk install everything mostly worked as expected. Kernel 6.8 before -31 gave an error during the debootstrap process discussed here:
https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/2058179

the only parts that need adapting in the script are;

1. The mentions of "jammy" that need to be replaced by "noble".
2. Apt sources are now no longer stored in /mnt/etc/apt/sources.list but in /mnt/etc/apt/sources.list.d/ubuntu.sources the layout is different too and for ubuntu desktop generated by ubiquity on a country by country basis.

What also happened was an error requestor window popping up on the desktop screen during the debootstrap procedure that had no impact on the install.

I also wan unable to export rpool before the reset at the end of Step 5. Which was resolved by just rebooting anyway and in busybox during boot importing the pool -f then exporting it there. rebooting after that everything worked.

What I would recommend though is adding a busybox compatible script for recursive rollbacks to initramfs images by adding an entry to /usr/share/initramfs-tools/hooks importing something akin to this:
https://gist.github.com/Boruch-Baum/13f15781eafbd8c2098eca081f3b09be

... standard prereq header....
copy_exec "/root/myExtras/zfs_recursive_rollback.sh" "/usr/bin/zfs_recursive_rollback.sh"

I would expect that most people want the option to boot in recovery in an initramfs only environment and be able to at least

• do a "zpool import -N rpool" to make sure nothing is mounted or tasks are running when snapshotting or rolling back
• do a "zfs snapshot -r rpool/ROOT@BeforeTryingSomethingWeird" to snapshot the non live system in busybox.
• do a "zfs_recursive_rollback rpool/ROOT@BeforeTryingSomethingWeird" to not have to rollback every dataset manually.
• do a "zfs destroy -r rpool/ROOT@BeforeTryingSomethingWeird" if everything worked out without having to worry about breaking things in a non usable recovery mode

So all in all the current write-up for 22.04 can be copy pasted with some minor changes. And since server 24.04 , unlike desktop 24.04 doesn't have zfs in the install option, the OpenZFS page will be the default goto for making a server install using zfs and wanting a good snapshot ability for easy maintenance.

Cheers.