Name: OpenZFS on OS X
Rating: 4.5 (1 reviews)

Overview

OpenZFS on OS X is the open source port of OpenZFS on OS X.

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.

Note: While the included package installers require OS X 10.8 or later, compiling OpenZFS on OS X from source will ensure compatibility with OS X 10.6.

What's new in OpenZFS on OS X

Version 1.5.2:

New upstream checksums (with new feature flags): SHA-512, Edonr, Skein (OpenZFS)
Resumable send and receive (OpenZFS)
Finder notification thread to refresh sizes across datasets (Jorgen Lundman)
SPL: enhanced kmem pressure system (rottegift)
SPL: Rewrite TSD using AVL tree (Jorgen Lundman)
Cache names in getattr (Jorgen Lundman)
InvariantDisks serial fixes (cbreak)
Show Hardlink LinkID fixes (Jorgen Lundman)
Trivial ACLs not hidden (Jorgen Lundman)
Group ACL fixes (Jorgen Lundman)
IOkit deadlock on export fixes (Jorgen Lundman)
MAF and deadlocks in ZVOL fixes (Jorgen Lundman)
Show diskutil info on ZVOLs fix (Brendon Humphrey, ilovezfs)
ZED notification fixes (Andreas Weinlein)
Have automatic import always use by-id (Justin Scholz)
Fix handling of XATTR_CREATE and XATTR_REPLACE (ilovezfs)
Don't ignore VFS when it passes nosuid and nodev (ilovezfs)
Don't use a shared lock for online expansion (ilovezfs)

10 OpenZFS on OS X Reviews

Hoondi

02 August 2014

Most helpful

I would like to share my thoughts with others and welcome feedback. I have used ZFS before it appeard on OSX and used it on OSX since 32bit PPC days... The first thing to keep in mind, is that there's been several attempts to kickstart this filesystem on OSX and even Apple intended to use it before Oracle bought out Sun Microsystems. These attempts are not a reflection of ZFS's features itself, but more so an issue of execution on the Mac OS X platform. Articles exist on the web that suggest once you starting reading around 12TB of data on spindles, you're statistically guaranteed to have encrounted a read error. (http://www.zdnet.com/blog/storage/why-raid-5-stops-working-in-2009/162). This is also known as silent data corruption, bit creep etc etc. The merit of the article or how accurate the "12TB" value actually is, isn't really something that should be discussed here, but the message is clear – the larger hard-disks become, the more likelihood read errors will occur when you read/copy the data. Think about his for a second: How often do you replace your storage? let's conservatively say every 5-7 years. (some only do it if a disk fails) And how long do you propose to live? let's say the "y" generation is going to reach 80+ no probs. So, if you transfer your data every 5-7 years, that's 12 occasions (minimum) of migrating/copying your data throughout your life. How confident are you that all your data will still be readable when you want to hand down photos of loved ones or movies of your children? If you're not storing your data that can be guaranteed consistent-on-disk by using block checksums, you may want to rethink a few things. Also, what I'm talking about here has nothing to do with backup strategies – that's another topic for discussion another time, but realise that if you cannot guarantee consistency-on-disk, all you're doing is potentially moving a hidden problem to your backup strategy. This all sounds fairly drastic and harsh, and this issue is essentially masked by current disk sizes, but with 6TB drives available, it's something you might want to carefully consider for the future. Being able to use checksums to verify your data is just one of the many features of ZFS, there are many more that no other filesystem can offer natively on OS X and so it's for this alone that I rate ZFS so highly. HFS is should've been retired years ago, (http://arstechnica.com/apple/2011/07/mac-os-x-10-7/12/) Even Apple know this by there decision to adopt ZFS back when Mac OS X 10.5 was being developed. How do you feel about your data sitting on HFS now? Hat's off to the guys developing ZFS on OSX, you guys rock! Regards, R.

Like (6)

Version 1.3.0

Current version is 1.8.2. Time for a small review. After nearly 4 years using OpenZFS, my early enthusiasm has waned... All in all, knowing how it has evolved, I kind of regret a bit my installing it. Not that ZFS has become a bad filesystem, but the development of the Mac port is really slow in fixing the issues, the devs don't have much time to dedicate to that project and you must make enough trials before updating to a new version. I had to skip a few versions last year before they fixed an important issue I had (took one and a half year before I can update with peace of mind...) — I don't even dare posting issues on their forum any more, as one dev has been pretty rude to me a few years ago, with no reason (see one of my posts below) and I generally get no answer. Luckily, the issues have always been non-destructive, and once you've got a version that works it's ok. I want to believe that if you dedicate a full disk to one big ZFS pool, you'll meet zero issue. But having a few pools scattered amongst HFS+ partitions like me is probably showing issues that wouldn't arise otherwise — and this is an issue for me, as ZFS is still not bootable, AFAIK. Well, I'm probably not the target for ZFS, after all, even though I can't update to MacOS 10.13 and enjoy APFS... So, if you absolutely need ZFS or are of the geek kind (like me ;-) ), go for it, but now that APFS is here, there's no need for ZFS for the average user.

Like (2)

Version 1.5.2

Aargl

11 February 2017

v1.6.1 is out and still compatible from 10.8 to 10.12.
(I've tested it on 10.9 and all seems ok)

Version 1.5.2

3 answer(s)

Aargl

16 April 2017

Just a word of caution: I've had issues with 1.6.1, later on, and found no way to circumvent them so I came back to v1.5.2.
I must also say that I've noticed small issues (regarding view options and other little things) which causes are still not identified. It may depend on my OS (10.9), who knows. The dev team is unable to reproduce my issues... :-/ (and doesn't have time to spend on it)
ZFS is still interesting for a lot of reasons but it has also limitations and you have to experiment well to see if it fills your needs.
For a typical desktop user, the ideal approach is probably to dedicate full disks to ZFS and create sparsebundles on them to avoid all potential issues while retaining the benefits.

Aargl

23 March 2018

v1.7.1 is out and one of the issues I had on OS 10.9 has been fixed.
Unfortunately, the other one is still there: the first pool I create is not recognized in some of my OS partitions after reboot... — it was in my test drive but then not after I updated OpenZFS in my main OS partition. :-(
Luckily, this doesn't affect existing pools.
This issue probably doesn't exist in recent OSes, according to the dev team's reactions, but if you want ZFS on 10.9, I strongly recommend to stick to v1.5.2 — even supposing there's something wrong with my main OS partition, I have no issue with v1.5.2!

Aargl

24 March 2018

Looks like the issue was (probably) due to remains of old versions of OpenZFS!
Even if they say you don't have to uninstall before updating, my experience convinces me of the opposite: after carefully uninstalling (with uninstaller 1.7.1 AND with uninstaller 1.5.2! plus some more file cleaning), all seems to be working fine again! :-)

Aargl

31 January 2017

v1.5.2 have been out a long time ago and is perfectly stable; there's actually a "1.6.0 Sierra RC1" available, but as its name implies, it might only run under Sierra... wait and see. You can read in their forum that sooner or later (will it be 1.6?) OpenZFS will be bootable, which should be really interesting. ;-)

Version 1.5.2

Aargl

23 October 2015

Current version is 1.4.5.

Like (1)

Version 1.3.1

Aargl

23 October 2015

A quick note after recent changes in their support policy: I had a mail from one of the devs saying "We have reached a point of overload in terms of supporting people with issues such as yours in the forums, and they have reached a point of disarray, bordering on disinformation. i.e. There are people out there who believe the software cannot be installed because you, and I mean specifically you cannot do so due to whatever circumstances you find yourself in."
Then "You have to realize that there are only 3 of us running this project, it costs you nothing to use the software, so we feel quite justified in dictating in what form we will attempt to deliver support."

So, I suppose it means that if you dive into ZFS, you have to be tech savvy enough to be sure that your issues are general issues... and not pollute the forums. ;-)
Good will is not enough, it seems.
Even if I understand the overflow they must face, that behavior put off my enthusiasm (to say the least...), especially because earlier this year I faced "real" issues that have been fixed thanks to the time I've spent trying fixes and communicating with the team — so I don't recognize myself in the portrait of "stupid user" thrown at me. ;-)

To conclude in a positive way, I must say that after ten months or so on ZFS, I had no issue at all regarding data security: mine were compatibility issues with specific softwares (indeed AVID ProTools and their interface drivers). Fixed.
Once it's all set up, you can just use ZFS partitions as any other (you can even manage them with Carbon Copy Cloner — not Superduper!).
Nevertheless, there are things to know before jumping in: it still doesn't support OSX permissions. I still have one issue, exclusively with ProTools wiping labels off its own sessions files (a really small issue, indeed, considering that all the other softwares I've tried aren't doing so).

Version 1.3.1

It doesn't take long to "feel" the superiority of ZFS over HFS: a few speed tests on copying huge files reveal faster writing and, if you activate compression, a space gain (a 37 Gb HFS became 35.4 Gb ZFS!) — it's actually even faster with compression on! Of course, the scope of ZFS is rather on data security, but I can only rely on what I've read, since it's just been 2 weeks I'm testing it (indeed because I discovered hundreds of bad blocks on an HFS drive... ;-) ). The principles behind ZFS are pretty reassuring: "copy-on-write", self-repairing mirrors... And the OpenZFS dev team is really responsive! I only give 4.5 stars, just because it's not fully integrated in OSX (no GUI, DiskUtility.app and other utilities don't deal with it directly and you will have to use Terminal for setting up and managing "pools"). Yet, it's very easy to create simple pools, and once you understand the concepts of it, you easily create a ZFS partition on your HFS drive without any issue. If you care about your data, ZFS is mandatory.

Version 1.3.1

1 answer(s)

Hoondi

10 April 2015

Well said Aargl, this software just keeps improving all the time...

I have been running this since the day Mavericks came out on a production system (before that on a virtual machine for test purposes). At this point I'd recommend it to anyone who wants to benefit from the advantages of running zfs. It is rock solid, and has all the niceties that one would expect (installer, disks automatically mount). It provides "zvols", which means you can have a zfs block device with all the zfs fun stuff (snapshots, auto healing, ...), and format it as HFS+. I'm using that to have TimeMachine backup to zfs.

Like (1)

Version 1.3.0

3 answer(s)

Xenophon

14 August 2014

Thank you. This is very helpful.

liv3010m

16 November 2014

Hi Macott, don't you mind to share how can I format a zvol as HFS+? because I'm having problem with my iTunes Library residing directly on a ZFS volume ( iTunes Posible unresolved transaction race null ... )
Thanks!

liv3010m

23 November 2014

Nevermind, I already figured it out. :)

Strob

02 August 2014

The developer's website states "It's compatible with OS X 10.6 through OS X 10.10 (Snow Leopard, Lion, Mountain Lion, Mavericks, and Yosemite). " Why is this marked here as needing OS X 10.8 and above?

Version 1.3.0

2 answer(s)

MacUpdate-Nick

03 August 2014

Hey Strob,
I just now saw that note on the website. We marked the min. OS as 10.8 due to the DMG containing a package installer for 10.8 and one for 10.9+. I'll see if I can get the correct requirement from the developer and update accordingly.

Thanks for letting us know!

MacUpdate-Nick

03 August 2014

It turns out compiling from source will allow users to run OpenZFS on OS X 10.6. The installers included with the dmg are indeed meant for OS X 10.8+, though. As such, we'll be leaving the requirements section as-is, but adding a note to the listing.

Hoondi

02 August 2014

Like (6)

Version 1.3.0

2 answer(s)

Virtualruffy

02 August 2014

Thank you for your information. I would like to ask though, if you would specify how zfs has benefited you in real world use and issues you've encountered in that use. A "what you can expect" guide, if you will.

Like (1)

Hoondi

05 August 2014

Hi Virtualruffy,
Here's a quick reply for you.

My setup:
One machine in the house acting as a server.
All other PCs connect to it for data storage, such as iPhoto, iTunes, iMovie, FCPro/X, AirMedia Server, Apache and PostgreSQL etc etc.
Currently shared out via AFP, SMB and NFS, but I tend to use NFS mostly.

Benefits:
Over the years, the server periodically scrubs the data checking for block integrity and "resilvers" any bad blocks. Any issues (a.k.a Silent Data Corruption, or Non Recoverable Errors) are brought to my attention through ZFS's "zpool status" command.
This has happened to me twice so far and each time I've replaced the disk and let the pool resilver.
ZFS's set of command line tools are very elegant. You essentially express your intent using english words which tend to be congruent with ZFS's zpool and zfs commands on the command line.

ZFS repairs blocks on the fly too:
When I request data, ZFS reads the desired blocks, recomputes the checksums and compares them to the original checksums. If for whatever reason the data is not valid ZFS will re-read the data from another area/disk in the pool, verify the checksums and only then deliver the data back to the system. It will also attempt to repair the blocks on the fly and record which spindle had experienced the error.
I can then run automated scripts to report on this behaviour via email, Applescript, Notifications etc etc.

If this were a conventional RAID system and actually managed to detect the error, it would have to rebuild the entire array using it's computed parity as RAID systems aren't that smart and know nothing about which blocks are in use and which blocks are not.
Crudely, ZFS is a Logical Volume Manager (LVM), is RAID capable and knows about block usage, thus it only needs to repair defective blocks. This can save days on large systems...

Issues:
Spotlight and certain other software only want to play with HFS... although unlike earlier versions of ZFS on OSX, OpenZFS can create zvols, (Think of them as HFS disk/sparse images that sit on top of another/different filesystem) such issues can easily be managed until the guys looks at implementing OSX specific features such as SL into OpenZFS.

This site isn't really the medium to go into much more detail Virtualruffy, plus I'm really enjoying the red we cracked open earlier, so I suggest you introduce yourself in the OpenZFS forum, ask your questions there and have far more knowledgeable people than me offer you guidance.

Cheers,

R.

OpenZFS on OS X

Overview

What's new in OpenZFS on OS X

10 OpenZFS on OS X Reviews

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