ZFS Comes to OS X Courtesy of Apple's Former Chief ZFS Architect

Apple's flirtation with ZFS, the file system backed by Sun, has been well-documented with rumors and speculation dating back to 2006. The interest was fueled in mid-2007 by a claim by Sun CEO Jonathan Schwartz that ZFS would supplant HFS+ as the file system for Mac OS X Leopard. While ZFS did not materialize in Leopard, Apple clearly continued to work on the project, with claims of some support appearing in marketing materials for Mac OS X Server Snow Leopard.

Optimism surrounding that development was apparently premature, however, as all mentions of the file system later disappeared from Apple's site amid claims that licensing issues had led the company to scrap the project. By late 2009, Apple had shuttered even its open source ZFS project site, indicating that it had abandoned all work on the project.

In March of last year, Ars Technica posted a lengthy profile of Don Brady, the 20-year Apple engineer who had helped transition to the HFS+ file system for Mac OS X and also headed up Apple's internal ZFS team from 2006 until it was disbanded in 2009. As the report notes, ZFS offers a number of advantages over HFS+, including a 128-bit structure to address large file and volume sizes, as well as features for simplifying data management and increasing data integrity such as copy-on-write technology to preserve the file system structure should errors or failures occur while new data blocks are being written.

At one time, there was a lot of hope that Apple might transition from HFS+ to ZFS as a more modern replacement. In particular, ZFS's automatic snapshot feature was believed to be the perfect fit for Apple's Time Machine backup tool. When Snow Leopard was first announced in 2008, it was slated to have full read-write ZFS support, at least in the server version.

But when WWDC 2009 rolled around, all mention of ZFS support was scrubbed from Apple's website. A patent infringement lawsuit was still pending between NetApp and Sun, with NetApp claiming that it held patents on copy-on-write. Furthermore, Sun's CDDL open source license was also believed to make ZFS incompatible with Mac OS X, and that Apple couldn't reach suitable license terms with Sun.

With Apple shutting down its ZFS project in 2009, Brady soon left the company to form his own venture, Ten's Complement, with a plan to bring ZFS to the Mac. Brady and Ten's Complement have been working on the project since 2010, with an extensive beta program having been underway for quite some time, and it now appears that the company is ready to begin rolling out its ZFS products under the ZEVO name. First off the line is the Silver Edition, which is now available for $19.95 and brings some of the basic advantages of ZFS to Mac OS X.

Z E V O's Silver Edition brings you sophisticated ZFS storage technology in an easy-to-use solution.

It's ideal for those wanting modern, reliable storage that is simple to set up, validate, and manage. Our Z E V O Storage Setup Assistant makes setting up a single disk for Z E V O a snap. In a few simple steps you'll be up and running.

zevo silver edition
The company will soon be releasing its more advanced products, including the $39.95 Gold Edition with such features as Time Machine-like rotating data snapshots and data redundancy. A forthcoming Platinum Edition carrying additional features such as RAIDZ support, data deduplication, and an advanced management utility is set to launch this spring, with pricing yet to be announced. Finally, the company is also working on a Developer Edition that will offer a combination of GUI and command line interface tools for complete system control.

Ten's Complement is not the only group to still be working on bringing ZFS to Mac OS X, as the MacZFS open source project continues to build on the foundation laid by Apple and Sun. But Ten's Complement seems to be the first to bring ZFS to the Mac in a commercial package to facilitate implementation and maintenance of the file system for users looking at options for securing the integrity of their data.

Top Rated Comments

Cougarcat Avatar
146 months ago
I've never seen any corruption on HFS. Also Arstechnica.com, while popular and full of good information, isn't 100% correct all the time.

It's not just Ars, it's John Siracusa. He's written 20+ page OS X reviews since the beta. He knows his stuff.

HFS+ is held together with duct tape and a prayer at this point. I hope Apple has something brewing, because I'm not sure how much longer they can keep slapping more stuff on top.

If you've read Siracusa's review (http://arstechnica.com/apple/reviews/2011/07/mac-os-x-10-7.ars/13), he suggests that Apple's work on Core Storage (the biggest change in the OS X FS to date) might be an indication of the direction they're going. A few years ago they were hiring filesystem engineers, so they're definitely brewing something.
Score: 13 Votes (Like | Disagree)
kolax Avatar
146 months ago
Love that he continued to work on it.

However, given the "silver, gold and platinum" rubbish, maybe they should have made this for Windows. One version for all, even if the average user wouldn't use those features.

I appreciate the amount of effort and time, but fragmented releases like that suck. Especially if you had a "silver" edition and suddenly wish you had the "platinum" edition, you'd probably have to reformat.
Score: 13 Votes (Like | Disagree)
iEdd Avatar
146 months ago
After reading title: "Oh awesome."
After reading rest of article: "Ah, nevermind."
Score: 12 Votes (Like | Disagree)
Peace Avatar
146 months ago
I remember those days of testing ZFS in OSX. We couldn't seem to fix the problem where an attached USB drive formatted as ZFS would go to sleep and BAM ! kernel panic. Back then ZFS needed to be constantly connected (R/W) to any partition that was formatted ZFS. This is why the team at Apple gave up on it.

Since my NDA with that group no longer exists I can say that now :)


It looks like he's fixed the problem.
Score: 10 Votes (Like | Disagree)
cg0def Avatar
146 months ago
Nice to see you guys covering Zevo. Ten's Complements has a great solutino but there's one issue that I really hope they've found a solution for. Time Machine drives apart from being a backup are also used as disaster recovery. If you store your backup on an FS that the OS does not by default know how to read, you will have a hell of a time restoring from it in the unlikely event of a disaster recovery. You would need some way to slipsteam the ZFS driver into the Lion recovery partition and then every time an OS update wipes out the hack you'd have to recreate it. The only other option would be the creation of a boot disk of some sort for the use of disaster recovery. I'd imagine that the first case breaks Apple's EULA and I am really hoping that Ten's Compliments has been working on creating a book disk of some sort. To be honest, for most OS X users, any backup other than a disaster recovery protection is a waste of time money and space.

Another problem is the fact that ZFS has absolutely no driver to Windows which is not quite the case with HFS but then again writing a Windows drivers is a bit out of the scope of Ten's Compliments.

Oh and as to why ZFS is something you need to care about here is a why:
HFS+ had gotten incrementally better over the years and I'd even go so far as to suggest that it's a marginally better FS than NTFS. However, the age of the FS is being hidden by the OS and in fact there are tons of hidden meta files that you never get to see. The problem with HFS+ and pretty much everything else out there is that they don't check for bit level file consistency. HFS+ however depends on the assumption that there are no bit level errors in your meta data in order to let you access your files. And when errors occur you are under a very very real danger of loosing your files. Apple would have you believe that it is impossible to ever loose files and then they'll go back and tie their pants by saying that you should always backup your files. Well here's what I know from personal experience. I had a set of data that I've been moving between OS upgrades and computer changes and hardware upgrades for the better part of 7 years. Yes, I do clean my preference files whenever it gets really messy. One day, after some sort of a combination of a hardware failure followed by a failed attempt of a software to save changes to a file, my whole documents folder literally disappeared. It was still there in terms of bits but HFS+ could not read it or repair the drive. Had that been ZFS, the error would have been caught long before occurring an ideally I would have known that the drive was failing with my data being written to the non failing parts of the disk (it was not a mechanical failure).
Anyway I lost some files and restored most but the point is even the best efforts of Apple can't quite cover up the fact that the FS design is a bit creaky 20+ years after it's creation.

As to Apple picking up ZFS once again, all is not at all lost. If I may point out, nowadays, Oracle does not have a single person from the Sun ZFS team working for them anymore. Stupid management decisions made it unacceptable for all the guys to stay there. ZFS improvements however, are still being contributed by those same guys. In fact the open source version of ZFS is currently the one that is ahead in terms of features and development efforts. There is still the issue of licence compatibility which I am not so sure if it really is an issue but my point is that if Apple ever chooses to reevaluate ZFS' suitability for OS X there is a very good chance of things turning out much different than they did last time.

Oh and a while back ArsTechnica did a very good piece of HFS+ and why a replacement is needed. Look it up for more details if you wish. It is factually correct.
Score: 8 Votes (Like | Disagree)
blackburn Avatar
146 months ago
We need a decent file system. I've experienced corruption with hfs+ but nothing as bad as with fat32 or ext2.
Score: 8 Votes (Like | Disagree)

Popular Stories

iOS 17 on Phone Feature

Gurman: iOS 17 to Provide Several 'Most Requested Features'

Sunday March 26, 2023 6:05 am PDT by
Apple changed the strategy for iOS 17 later in its development process to add several new features, suggesting that the update may be more significant than previously thought, Bloomberg's Mark Gurman reports. In January, Gurman said that iOS 17 could be a less significant update than iPhone updates in previous years due to the company's intense focus on its long-awaited mixed-reality...
iOS 16

iOS 16.4 Will Add These 8 New Features to Your iPhone

Sunday March 26, 2023 8:06 am PDT by
Following nearly six weeks of beta testing, iOS 16.4 is expected to be released to the public as soon as this week. The software update includes a handful of new features and changes for the iPhone 8 and newer. To install an iOS update, open the Settings app on the iPhone, tap General → Software Update, and follow the on-screen instructions. Below, we have recapped eight new features and...
apple mixed reality headset concept by david lewis and marcus kane

Some Apple Employees Seriously Concerned About Mixed-Reality Headset as Announcement Draws Closer

Sunday March 26, 2023 8:25 am PDT by
Some Apple employees are concerned about the usefulness and price point of the company's upcoming mixed-reality headset, The New York Times reports. Apple headset concept by David Lewis and Marcus Kane Initial enthusiasm around the device at the company has apparently become skepticism, according to eight current and former Apple employees speaking to The New York Times. The change of tone...
iOS 16

Apple Releases iOS 16.4 With New Emoji, Safari Web Push Notifications, Beta Changes, Voice Isolation for Calls and More

Monday March 27, 2023 10:03 am PDT by
Apple today released iOS 16.4, the fourth major update to the iOS 16 operating system that initially came out last September. iOS 16.4 comes two months after the launch of iOS 16.3, an update that added Security Keys for Apple ID. iOS 16‌.4 and iPadOS 16.4 can be downloaded on eligible iPhones and iPads over-the-air by going to Settings > General > Software Update. It can take a few minutes...
Steve Jobs Theater dusk

Apple Reportedly Demoed Mixed-Reality Headset to Executives in the Steve Jobs Theater Last Week

Sunday March 26, 2023 5:53 am PDT by
Apple showcased its mixed-reality headset to the company's top 100 executives in the Steve Jobs Theater last week, according to Bloomberg's Mark Gurman. In the latest edition of his "Power On" newsletter, Gurman explained that the "momentous gathering" is a "key milestone" ahead of the headset's public announcement planned for June. The event was intended to rally Apple's top members of...
top stories 25mar2023

Top Stories: iPhone 15 Pro Design Leak, iOS 16.4 Coming Soon, and More

Saturday March 25, 2023 6:00 am PDT by
We're still almost six months away from the official unveiling of the iPhone 15 lineup, but it seems like every day we're learning more about what to expect from the next-generation models. Notably, this week gave us our clearest look yet at what appear to be some changes for the volume and mute control hardware. iOS 16.4 and associated releases are also right around the corner with some new ...
apple tv 4k red image

Apple Releases tvOS 16.4 for Apple TV 4K and Apple TV HD

Monday March 27, 2023 10:00 am PDT by
Apple today released tvOS 16.4, the fourth major point update to the tvOS 16 operating system that came out last September. Available for the Apple TV 4K and Apple TV HD, tvOS 16.4 comes two months following the release of tvOS 16.3. The tvOS 16.4 update can be downloaded over the air through the Settings app on the ‌‌‌‌Apple TV‌‌‌‌ by going to System > Software Update....