zfs on Linux has not been production ready for decades. People have lost data from it. There's no real reason to allow the default installer to do this.
If you understand the risks, you can do it yourself.
> zfs on Linux has not been production ready for decades. People have lost data from it.
I don't think that's true. Other than with ZFS-native encryption, which I grant has been less reliable, it's been rock solid for a very long time. And I've run >1PB of postgres databases on it professionally, so I feel fairly comfortable in that assertion.
> There's no real reason to allow the default installer to do this.
The default Ubuntu installer at least used to support ZFS, which is the point.
If you Google zfs Linux data loss, you can find many posts about this. Including one lengthy discussion on HN.
Also, you are not the typical user installing the OS from the default installer. I am not saying ZFS is bad, but not including it in the default installer is no big deal.
So funny thing. I was planning to agree and write something about how you can find data loss stories for literally any filesystem, but the relative frequency and nature of those stories is important to differentiate.
https://duckduckgo.com/?t=ffab&q=zfs+data+loss&ia=web - First result is someone claiming data loss after setting sync=disabled on a single disk over usb with slog+l2arc on the same disk, and scrub turns up 50k errors; i.e. they did everything they could to hold it wrong, and in the end their disk physically failed, which I really don't think is a ZFS problem. Second result is a stack overflow thread discussing why ZFS doesn't fail the usual ways. Third result is official docs. If I go down the rest of the first page of duckduckgo results, it's mostly discussions of how ZFS protects against data loss, with the one exception of https://forum.level1techs.com/t/solved-zfs-monthlong-changes... ... which looks bad until you realize the use didn't mount a filesystem, and once they found it they recovered their data just fine.
So no, based on random web searches I conclude that ZFS remains head and shoulders above every other option.
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Edit: If I search for "zfs Linux data loss hacker news", I get https://news.ycombinator.com/item?id=22005181 which appears to contain zero stories of losing data on ZFS, although there's a bunch of stories about BTRFS doing so. Most of the remaining results are news stories about a single bug from 2023 and one story about ZFS's native encryption having problems (which I grant is a footgun).
I feel like the difference is that Kubuntu installer is specifically intended for users wanting the Desktop experience via KDE, whereas the Ubuntu installer can be used for multiple use-cases such as headless Servers or Desktops. Server admins might have reason to run zfs for root, but typically Desktop users are not really needing zfs when they have 1 or maybe 2 disks. There are other filesystems that provide some of the primary features without the overhead of zfs.
If one knows they want/need a zfs root on their Desktop, then they are likely capable of getting the KDE packages setup through the main Ubuntu installer without needing the Kubuntu installer.
As a desktop user I definitely have a lot of benefit of ZFS even with one drive. It's got bitrot check, copy on write (better crash protection than journals) and snapshots. All life savers especially on desktop. ZFS doesn't only shine on big arrays.
And yes you can do that but I don't use Ubuntu a lot and I hate gnome so obviously I tried setting it up through kubuntu when I wanted to give it a spin.
I'm not a fan of Ubuntu anyway due to systemd and snap but these days I'm on FreeBSD as daily driver and very happy with it. It was just when I was last deciding on an OS that I tried it. Also tried arch and manjaro and a few others but I didn't feel at home there either.
