Apple's new kick-butt file system pushes on

Apple's new kick-butt file system pushes on

Summary: Fixing data corruption before it startsApple is moving quickly ahead with their plan to give Mac users the most reliable data storage on any desktop with the new file system ZFS. According to MacRumors the latest developers build of OS X Leopard includes V1.


Fixing data corruption before it starts Apple is moving quickly ahead with their plan to give Mac users the most reliable data storage on any desktop with the new file system ZFS. According to MacRumors the latest developers build of OS X Leopard includes V1.1 of ZFS.

ZFS is the first desktop file system with true end-to-end data integrity. Thanks to sophisticated tree-based checksums it detects and corrects silent data corruption anywhere in the data path: disks, cables, interfaces and more.

Apple's Mac OS 10.5.0 - Leopard - is expected to be released late this month. It will include a read-only version of ZFS. The V1.1 ZFS in the developer's preview includes full read/write capability. This suggests that by the end of February, ZFS will be available (in 10.5.1) for users with large data pools.

While there is no word yet on when Mac users will be able to boot from ZFS - thus enabling its use on single disk systems such as notebooks and small desktops - I predict that in summer '08.

Why ZFS is important If you've ever had to reinstall an application, operating system or a driver that suddenly wouldn't work or had a "file not found" error, you've probably been a victim of silent data corruption. It is hard to tell since no operating system has an error message for it.

As I've documented (see Data corruption is worse than you know, How Microsoft puts your data at risk, 50 ways to lose your data and How data gets lost) silent data corruption is a real problem with today's desktop and server file systems. And it's getting worse as disk drives capacities grow.

Microsoft's aging NTFS can't compete Once ZFS becomes the default file system for Mac OS X, all the average user will notice is that their Mac is even more reliable. Other ZFS features, such as RAID Z, will mostly be of interest to media and scientific professionals with very large data sets.

In the server world though, all the Windows buyers will have to explain why they prefer a system with more data corruption to one that is provably more reliable. And big corporate customers will have another cudgel to beat price reductions out of Microsoft.


The Storage Bits take ZFS, an open-source product developed by a small team of smart Sun engineers - I know, I've met them - is a game changer for the industry. All popular file systems have had roughly the same level of data integrity so no one mentioned the problem.

Now, however, Sun and Apple will soon have the best data integrity story in the industry. Apple's Time Machine will give Mac the best back up story as well. Microsoft and the Linux server folks will have to respond. We, the users, will win, no matter which platform we prefer.

In the meantime, Apple and Sun will make hay while competitors play catch up.

Update: Microsoft fans, I presume, having forgotten how enthusiasm for new software feels, have intimated that I must have a financial or business relationship with Sun, Apple, ZFS or something. Sadly, I don't. My condolences to those whose software updates inspire fear and dread.

Update II: If you want to learn more from a "dirt-under-the-fingernails" engineer about ZFS, check out this post from file system engineer Drew Thaler Don't be a ZFS hater.

Comments welcome, as always.

Topics: Apple, Hardware, Microsoft

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  • Sounds similar

    to ReiserFS 4... ]:)
    Linux User 147560
    • (nt) Yeah, I heard ReiserFS 4 is a "killer" FS!

      • Ouch!

        Nice one! :)
      • aside from the tasteless joke...

        ReiserFS4 is faster than ZFS, but as I understand it, less robust from a data integrity standpoint. Also, I don't know of anyone taking over the project after Hans Reiser's murder indictment, but I haven't really had any motivation to check on it.

        In highly sensitive environments, data is written on a mirrored RAID array (e.g. RAID 1, but combination of mirror and striping [spreading data across disks for speed] also exist in RAID 1+0, RAID 5, RAID 5+1 or RAID 6), so data integrity is preserved, even with the loss of parts of a file or disk.
      • speaking as a Linux user

        you aren't the only one. That's why I go with the tried and true ext3. . . the "ZFS-like" FS upgrade Linux users should wait for is ZFS itself, I believe that the political problems with licensing will be worked out sooner or later.

        There's also work going on with running ZFS in userspace, apparently the licensing problem doesn't apply and this would allow the FS to run independently of the kernel.

        Either way, I'm willing to wait until ZFS shows up in my Debian automatic updates to run it.
    • OK. What's your point? (NT)

      • If you have to ask

        then you will never get it even if it's explained. ]:)
        Linux User 147560
        • Still, why not be courteous? and enlighten us! - NT

        • The sky is blue

          during the day.

    Competition in a MEANINGFUL way, not just bells and whistles!

    Open source seems to be good.
    • Still longing for the day

      when a geek actually gets that some "bells and whistles" really are meaningful interface elements.
      • You are right

        Beryl's bells and whistles are meaningful interface elements, unlike any of those found in either OSX or Vista.
        • If you only knew: Mac OS X GUI elements make you more productive.

          NonZealot writes: "unlike any of those found in either OSX "

          Have you tried Expose? You don't know what you're missing.
          • Hehe, Expose is cute

            but it can't compete with [url=] Beryl's scale effect [/url]

            Expose by itself is nearly useless. It only becomes useful when it is combined with all the other features that Beryl has to offer.

            [i]You don't know what you're missing.[/i]

            Actually, it sounds like [b]you[/b] are the one who doesn't know what he is missing. :)
          • Expose

            So Apple creates Aqua, Expos? and everything else, and now
            Beryl copies and now Beryl is the man, I don't think so.

            I love many of it's effects, specially being able to bend a window
            to look behind it when I need a quick glance at some info, but to
            put OSX down on this subject is hipocritical.

            Expos? and everything else was completed by Apple first.

            Before that, Linux looked like just another Windows clone..
          • is that supposed to be a joke?

            is that supposed to be a joke? Beryl's scale effect is a copy of part of Expose... Expose does all that and more...
          • I hope you are being sarcastic?

            I followed the link you gave and took a look at the first screenshot ( I sure hope this isn't the best they can do, look how poorly the windows are scaled down!
          • Of course, since you've never used OS X...

            your comments are, of course, as always, ignorant, and almost a complete waste of

            I say "almost" because I got a chuckle out of this quote from your link:

            "OS X Expose Like Effect"

            Too bad you have no idea what Expose really is, and why Beryl is copying it.
          • Wow!

            I am an OS X user and didn't know about Expose until I read this thread - cool stuff! Makes me even happier to put Windows behind me.

            For some of the other posts - it's really a little dumb to argue that a self-correcting file system isn't a significant & praiseworthy feature, and to applaud Apple for getting it to market first. And since it sounds like ZFS is open source, maybe Linux AND MS can just jump on board at some point so there is a common file structure for everyone? Is that so hard?!?!?
          • WOW , so you're telling us now that Windows has Beryl . <NT>