That's not likely to happen for both licensing and technical reasons. CDDL is not an acceptable license. And OpenBSD also has no extant framework for loadable kernel modules, nor any desire to add one (increasing attack surface).

I understand the CDDL is not GPL-compatible, but why is it not acceptable for OpenBSD?

It's still copyleft, so including it into the base system would require licensing those parts as CDDL, so the system as a whole would no longer be BSD-licensed.

Only the files pulled in would fall under the cddl. The cddl is unlike the GPL in that it is file based copyleft. It doesn't force any other part it is combined with to be any license. Ie you could combine it with anything that is ISC or BSD licensed without issues.

What files wouldn't be pulled in in an implementation that doesn't support dynamically loaded kernel modules?

But anyway, even one file is enough. The aggregate would no longer be clean BSDL.

In fact, they recently removed loadable kernel support. OpenBSD 5.6 is the last release to support this.

Of course, you don't need loadable kernel module support to extend the OpenBSD kernel.

My pie in the sky is for them to eventually port HAMMER2 from dragonflyBSD to OpenBSD.

Is it production ready or a research filesystem?

I don't think it's production ready and I also don't think it's a research file system?

It seems like a passion project from Matthew Dillon who seem to be crazy smart. I mean he fork and created his own BSD and then decided let's do HAMMER2 while we're at it.

Apparently it's one of the fastest for things like postgresql. Here are some benchmarks: https://www.phoronix.com/scan.php?page=news_item&px=HAMMER2-...

HAMMER2 is already the default on Dragonfly.

I get the feeling that HAMMER2 will show up first.

I doubt HAMMER2 will become as mature and complete as ZFS anytime soon. Though it would be better than nothing I guess.

This is mostly about HAMMER2 being far more likely to get ported/merged to openbsd than zfs.

I understand, but I would prefer ZFS since it's way ahead of everything else.

My exposure to ZFS was a nightmare. it was being used for user home directories on a HPC cluster. Frequent outages, storage offline for days for recovery. I wasn't involved on the administrative side, just saw it from the user side. It was also many years ago, no doubt it has improved.

ZFS does seem to be miserable if you're installing it for the first time. I set my antergos installer last night to use ZFS for the root partition. Did not work once I rebooted. As much as I want to like ZFS, I don't think the tooling is there. My filesystem choice should be completely transparent.

I run a HPC cluster. I’m pretty bad at it so outages do happen but not like that. There are an infinite ways to fail at storage, nothing specific to ZFS.