OpenZFS was announced in September 2013 as the truly open source successor to the ZFS project. Our community brings together developers from the illumos, FreeBSD, Linux, and OS X platforms, and a wide range of companies that build products on top of OpenZFS.

OpenZFS is an outstanding storage platform that encompasses the functionality of traditional filesystems, volume managers, and more, with consistent reliability, functionality and performance across all distributions: illumos Webpage GitHub FreeBSD Webpage GitHub ZFS on Linux Webpage GitHub ZFS-OSX MacZFS GitHub


The high-level goals of OpenZFS are:

  • to raise awareness of the quality, utility, and availability of open source implementations of ZFS

  • to encourage open communication about ongoing efforts to improve open source ZFS

  • to ensure consistent reliability, functionality, and performance of all distributions of ZFS.

The main technical goal of OpenZFS is easier sharing of code between platforms. Strategies include:


ZFS-OSX brings OpenZFS features to MacZFS.

ZFS-OSX is a well-developed alpha that is ready for testing by people who are happy to use Terminal. It's designed for use with Mac OS X 10.6 – OS X 10.9 (Snow Leopard, Lion, Mountain Lion and Mavericks). To begin testing the most recent build

ZeroBSD | OS X with ZFS offers an approach to obtaining the most recent code, building from that code and installing the built software. To test without building

Disk images are ocasionally added to – aim for the most recent .dmg file. The image will contain built software – binaries, kernel extensions (KEXTs) and so on – that may be used with or without installation.

These images are not designed to include the most recent fixes or enhancements. If in doubt, please ask in IRC:

The simplest approach

Expect a user-friendly package – for use with Apple's – before the end of 2013. Suggested focus areas for testers

A ZFS file system for your home directory

  • where ~ is the root of that file system.

A ZFS file system containing multiple home directories. Notes

ZFS-OSX is not yet feature-complete.

Alpha software should not be used with data that is of significant value. Be thorough with your backups and please remember that ZFS alone is not a substitute for a good backup strategy.

If you're limited to Leopard, or if you require the most stable MacZFS at this time, then instead of ZFS-OSX: consider relatively old version 74.3 of MacZFS.

If you normally use MacZFS 74.3 or ZEVO: you must uninstall that software before testing ZFS-OSX.