The ins and outs of Apple’s new file system, APFS

“With macOS High Sierra, Apple has introduced a new file system called APFS (Apple File System),” Kirk McElhearn writes for Intego. “Apple has already rolled out APFS to hundreds of millions of devices: your iPhone and iPad. When iOS 10 was released, APFS was included, and the upgrade was, for the most part, seamless. Of course, the way you use files on an iOS device is different; you don’t have the same options for creating, moving, or deleting files that you do on a Mac.”

“macOS High Sierra will upgrade your startup drive to APFS by default if you are using an SSD or hard drive. However, it is not currently ready for Fusion drives, so if you’re using a Mac with one of these, you won’t be upgraded,” McElhearn writes. “Apple should release an update to High Sierra in the near future that supports Fusion drives.”

“Security is one of the key elements of APFS, and it manifests in several ways. First, the file system offers encryption at the file system level, not the disk level as it was previously,” McElhearn writes. “APFS can also make ‘snapshots’ of your drive, which record the state of all its files at any given time. They are very efficient, since they start with a basic list of files, then each subsequent snapshots records only what has changed (this is similar to the way Time Machine backs up your files). APFS also has features that improve the integrity of your data, preventing it from corruption caused by hardware (such as bad disk sectors), or crashes.”

Read more in the full article here.

MacDailyNews Take: When suport for Fusion drives arrives, Apple will have made on of their most spectacular transitions ever, on par with the move from PowerPC to Intel.

macOS High Sierra and APFS: Cautions! – October 6, 2017
Apple releases macOS High Sierra 10.13 Supplemental Update with fix for APFS Disk Utility bug and Keychain vulnerability – October 5, 2017
What you need to know about transitioning to APFS in macOS High Sierra – August 30, 2017
Apple just pulled off one of the great engineering feats of all time – March 29, 2017
Apple dials up encryption even further as mobile threats soar – March 28, 2017
Apple’s iOS 10.3 delivers brand-new Apple File System – March 28, 2017
iOS 10.3’s longer than usual installation likely due to switch to new Apple File System – March 28, 2017
Apple releases iOS 10.3, watchOS 3.2, and tvOS 10.2 – March 27, 2017
You must back up your iPhone and iPad before upgrading to Apple’s iOS 10.3, due soon – March 10, 2017
Apple’s iOS 10.3: A very, very important upgrade – January 25, 2017
APFS: What Apple’s new Apple File System means to you – June 24, 2016
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. To date, tools like Disk Warrior do NOT support APFS. If your drive goes FUBAR with APFS it will be Apple’s Disk Utility or nothing.

    From the website:

    • What can you expect soon

    We are working furiously to release DiskWarrior 5.1. The flooding from Hurricane Harvey resulted in a loss of 3 weeks of productivity for our developers. DiskWarrior 5.1 will more gracefully deal with APFS and the new KEXT security as follows:

    1) APFS disks will display in the list of disks. APFS disks cannot be rebuilt with DiskWarrior 5.1. Our developers are waiting for Apple to release the final APFS format documentation in order to safely rebuild APFS disks.

    2) The system extension “OS X services failure” message from DiskWarrior 5.0 has been replaced with instructions on how to allow the kext to be loaded. This will happen as DiskWarrior 5.1 is launched instead of during a rebuild. You will only need to allow the system extension once.

    • What’s in the works

    The next major release of DiskWarrior will include the ability to rebuild APFS disks.

  2. Apple has it’s priorities all wrong. Too many emojis, not enough APFS development. Several years late, well after Microsoft had cleaned up its file formatting with error detection and correction features, Apple stumbles out of the gate with APFS. As of today, it’s still not error free.

    The current leadership of Apple may be good at taking money from the iOS closed ecosystem fashion consumer addicts, but they demonstrate daily that they no longer have the chops to retain the lead in personal and professional computing.

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