What macOS Sierra’s new Apple File System means to you

“Sometime next year, Apple will start using a new file system on all its hardware,” Edward Mendelson writes for PC Magazine. “The new Apple File System (APFS) will replace Apple’s old HFS+ file system, used on all Macs since 1998 which in turn was based on the archaic HFS, introduced in 1985.”

“For now, APFS is available in the developer beta of Apple’s next-generation OS, macOS Sierra,” Mendelson writes. “Most users won’t notice anything radically different about hardware with APFS on the hard disk, but a lot of subtle differences are hidden below the surface. Most notably, APFS uses integrated encryption instead of the essentially tacked-on encryption technique used by the existing OS X FileVault feature that slowly encrypts or decrypts an entire drive. APFS can encrypt whole disks and individual files with separate keys for the file and its metadata, giving granular control.”

“Apple’s current file system time-stamps files with one-second precision, not enough to keep track of file changes with today’s hardware. APFS time-stamps files with one-nanosecond precision,” Mendelson writes. “Other advantages of APFS disks include flexible space allocation, so that two APFS “disks” can borrow disk space from each other when they need it, and not be limited by the space allocated to them when they were created.”

Read more about what APFS means for Apple device users in the full article here.

MacDailyNews Take: APFS was a long time coming, but sorely needed. It’s going to improve the whole experience from cloud storage to speed!

APFS: New Apple File System promises more speed, flexibility, reliability – June 17, 2016
The feds’ll hate this: Apple’s new APFS file system ‘engineered with encryption as a primary feature’ – June 14, 2016
Buh-bye HFS+, hello APFS (Apple File System) for macOS! – June 14, 2016
Apple can do better than Sun’s ZFS – October 26, 2009
Apple discontinues ZFS project, turns attention to own next-gen file system – October 24, 2009
Apple’s Mac OS X Snow Leopard Server’s ZFS goes MIA – June 9, 2009


  1. so, any guess when you think macOS sierra might be available to adorable little american girl constitutionalists. sometime next year is pretty vague. it’s like the dream i had last night. i don’t remember.

    1. Already here if you use the macOS Sierra beta. Consumer version is ‘This Fall’ according to Apple. Full across-the-board implementation will be happening in ‘sometime in 2017.’ Expect that Apple will need to implement on all their internal servers first, then their cloud storage servers, then force updates to all iOS, watchOS, tvOS and macOS devices.

    2. TechTard journalists have made a hash of all this.

      1) Sierra will be in beta this summer and will be made public this fall.

      2) APFS (Apple File System) is entirely separate and NOT part of Sierra. APFS is scheduled to be finished some time in 2017, as in probably over a YEAR from now. It will NOT be required. It will be bleeding edge technology for geeks. It will most immediately be useful to businesses because of its feature set for security, both backup and encryption. I can’t imagine much benefit in 2017 for average macOS users. Possibly, Apple will make it standard in whatever version of macOS comes out in 2018, not 2017.

    3. adorable little american girl constitutionalists should not rush to adopt the new file system for any data she really cares about, unless she has extremely secure backups. Grumpy old American constitutionalists have learned to fear major operating system changes and let others discover the pitfalls and hazards in new systems.

      1. haha, grumpy old american constitutionalists. i’ll take one of those any day of the week over a nice looking guy with a glittering, delusional and polished chavez disposition.

  2. I’ve seen nothing new that specifically deals with bit rot.

    With people now having files that can go back many years and people keeping hardware for 5+ years with the original hard drives (this will become even more “interesting” in the future as SSDs become the standard “hard drives”) specifically dealing with bit rot is a necessity. (Bit rot has been a concern of large corporate data bases for years — actually dating back to the 800 bpi open reel tape days. It’s just now becoming a concern in the non “big data” space.)

    As an example look into ZFS and some other modern file systems. Some recent variants have specific functionality to deal with this.

    Maybe APFS will have functionality that will address this directly, but so far I have not read anything to make me believe it does.

    1. The solution is simple: upload everything to the cloud and let the big companies deal with it. Then everything on your machine is just a downloaded duplicate copy that’s only even there while you’re viewing/editing it.

      I’m not sure how Apple handles iCloud, but I do have experience to know that big corporate cloud database services are regularly backed up daily, and still backed up to tape after a while.

    2. As long as the SSD is powered on occasionally I don’t think this is an issue. The drive controller’s firmware should take care of data integrity. The filesystem implementation is additional security against data corruption risk on top of that but likely not as robust.

      I am interested to know if file-level encryption keys are obliterated in some effaceable storage during a delete so we can actually get to high-confidence, low-resource file erasures. That would be awesome, for both users and security-conscious organizations! I know we could assume help from trim but that’s placing a lot of faith in a lot of unknowns working as desired and not even as intended…

  3. Kate:
    Tape backups alone are not enough to prevent bitrot. Let’s say there’s a 1 in a billion chance for a single bit on your hard drive to randomly flip the other way. 1 becomes 0 or 0 becomes 1. Seems unlikely, but we have terabytes of data now, so that tiny little chance is actually fairly common. It’s rare to notice it right away, maybe a song will have a click in it hat wasn’t there before, an image may become garbled or a movie stop playing correctly at a certain point. Wedding photos and videos are just sitting there for years waiting to degrade. Let’s say you back up once a week. How could you possibly check through all those files and verify that none have unexpected changes?

    Bitrot protection handles this. It knows which copy is the correct one and automatically detects and repairs these errors. If you don’t have a system in place your corrupted files will eventually be the only version you have backed up. ZFS handles this automatically, and part of the expectations for a modern file system is bitrot prevention. Even the cloud is not immune to this if their system isn’t intentionally built to prevent it, and most aren’t. Tapes are not enough.

    1. Is there anything that can be done by the user now to minimise the possibility of betroth? Like maybe occasionally moving files to another drive and back? Is it something that happens when a file is left untouched for a long time or can it happen say the next day after opening it? Are drives that are removed from the computer and stored for archiving vulnerable as well?

  4. Faster I/o and geeky UNIX things like increased inodes, flexible storage pools and verify on write sound like wonderful advances. Completely encrypted file systems with separate keys for files and metadata.. Suppose you have a hard disk crash. Yes even ssd scan crash. If there is not a clean unencrypted backup somewhere, all your data is lost. I don’t think that part of the picture is so good,

  5. AGAIN: The APFS (Apple File System) is NOT NOT NOT on macOS 10.12 Sierra.

    APFS is ENTIRELY separate from Sierra. Sierra runs on HFS+.


    APFS has a WISHLIST of features that are NOT YET REAL.

    *sigh* APFS isn’t even in beta yet. All Apple did was offer a ‘preview’ (unfinished) version of APFS that developers could play with. That’s all. Consider APFS entirely SEPARATE from Sierra, even though APFS will run on Sierra.

    I bet I’m shouting to the choir here and merely venting my annoyance at the techTard journalists who repeatedly mess up describing APFS. As such, please excuse my blether. 😤

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