What does Mac OS X Leopard’s use of ZFS filesystem mean to Mac users?

“We’ve seen a flurry of articles this week about the coming role of Sun’s open-sourced ZFS storage system in Mac OS X 10.5, Leopard. What we haven’t seen much is what it means to users and consumers,” Carl Howe writes for Blackfriars’ Marketing.

“The simplest way to describe ZFS is that it is a complete rethink of how computers store information. Everyone today thinks about storing files on a disk… Now Mac users have been pretty insulated from the whole C: drive insanity that PC users have put up with for the last 26 years (yes, since 1981), but even with such luxuries as having hard drives named ‘Insanity’ or ‘Starship Enterprise,’ we’re still hostages to the model that files go on disks, and if disks fail, users wail,” Howe writes.

“Now ZFS has a different model. It believes that users being aware of disks is so last century. ZFS deems all your disks a ‘pool’ of storage. It manages those disks for you; you only deal with files. Want to add more storage? Just add another disk to the pool, and ZFS knows what to do. Want to replace a disk? Tell ZFS to remove it from the pool, and it clears it off for you. You don’t know where or how many copies the system is storing — you just know that they are always there for you. Even better is the fact that it explicitly looks for bit rot and can correct it on the fly. It’s that smart,” Howe writes. “Oh, and did I mention that it will actually run faster under heavy disk loads than just about any storage system runs now?”

Howe writes, “Windows Vista STILL has letter-drive-based storage models hidden under its flashy GUI today. It will take years for Microsoft to cast off that disk-based legacy and all the business processes that accompany it. In the meantime, the productivity and innovation edge that ZFS gives Apple will even more of a lead over it Windows competitors than it has now. And that all translates into more sales for Apple’s computer business.”

Full article with much more here.


  1. ZFS is a very big deal and Carl Howe scores again with an incisive article.

    It will take a while for ZFS to mature, but soon Apple and Sun will be far ahead of the competition, especially in the enterprise. And with Leopard already certified as one of the four official Unix operating systems, the tipping point in the enterprise will come as surely as in the consumer market.. MS is fscked.

  2. Everyone writes about this as though this is going to be some Leopard only technology, or that this was some kind of Apple inspired enhancement to data storage and filesystems technology. The truth is, that neither of these are true. People also hype ZFS without realizing that it won’t be the perfect filesystem for all circumstances. The truth is, there aren’t really that many great advantages that ZFS is going to bring to the desktop, that HFS itself either doesn’t already possess, or couldn’t possess with some minor modifications. For the even bigger changes that ZFS provides, they too could be provided on HFS if apple ever decided the next version of HFS were to break backwards compatibility. Inevitably, whether a new HFS version with ZFS like features or a totally new ZFS filesystem, both would require breaking backwards compatibility.

  3. ZFS sounds interesting.

    Windows legacy will be a boat anchor around the neck of Microsoft’s OS. The shift will become exponential as Apple begins to extend years beyond Microsoft’s feeble capabilities – due to backward compatibility support.

    Apple has all the potential and almost unlimited growth area as MS withers and dies. And Good riddance to MS.

  4. ZFS is currently read-only in 10.5 but a recent developer preview of ZFS for Leopard has full creation/read/write abilities. Expect this functionality to appear in a dot release to Leopard within months.

    This is a VERY big deal for Apple and the enterprise – and kudos to the folks at Sun for making it open-source.

    @Joe – you are so wrong on many counts. Understand how ZFS works before pontificating.

  5. I look forward to getting ZFS when it’s ready, but the article is a huge embarrassment for Blackfriars — they claim that ZFS is already in 10.5 (for end users), and it’s not. They claim that ZFS is the basis for Time Machine, and it isn’t.

    They’ve got their facts wrong, and they need to correct the article pronto, and MacDailyNews should add a disclaimer as well.

  6. “ZFS deems all your disks a ‘pool’ of storage. It manages those disks for you; you only deal with files. Want to add more storage? Just add another disk to the pool, and ZFS knows what to do…”

    Is the software magic behind ZFS similar to that employed in the Data Robotics DROBO storage unit, that manages data across several hard drives and allows the user to swap drives in and out on the fly?

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