It’s nice that HAMMER2 is getting ready.
What sorts of features does HAMMER2 offer?
It’s supposed to be ZFS-like, but without its big overhead. For now it’s experimental and not yet feature-complete.
Still, it seems stable enough to include support for it in the installer for wider test coverage.
At least for HAMMER (1?), I’ve seen very large RAM requirements listed, and DragonFly didn’t work on my bhyve VM until I gave it a ton of memory. Meanwhile, ZFS works fine on 512MB machines. The overhead is kind of a myth, honestly.