@sourcerer @stefano Yeah, that's true.

ZFS do a lot of memory caching to avoid read calls, and the structure is generally better than UFS2 so the performance is. It's also that when you use FreeBSD the only filesystem you'd most likely use is ZFS. UFS2 doesn't natively support journaling, I think you'd need geom journal module as the back.

Netflix seems also uses UFS2, but mainly because ZFS structure can't allow sendfile call as Netflix wants. So that's where UFS2 is in production.

FreeBSD definitely has better support for ZFS. I'm wondering about others too, such as OpenIndiana...