[kenmazy]

Regarding zfs: the zfs on linux project (http://zfsonlinux.org/) is actually fairly mature and has decent performance ( though there are still some outstanding issues with using zvols as xen filesystems, and also if using a xen paravirt kernel ).

[justincormack]

But not being able to distribute binaries is inconvenient http://zfsonlinux.org/faq.html#WhatAboutTheLicensingIssue