macOS High Sierra and APFS: Cautions!

“Along with the release of the first developer beta of macOS Sierra in June of 2016, Apple included a prerelease version of the Apple File System (APFS), a major update to the previous file system, HFS+, which was released in 1998 as an update to HFS,” Gene Steinberg writes for The Tech Night Owl. “So you have such goodies as 64-bit support, robust file encryption, improved performance and efficiency, superior protection from disk catalog damage, and, under some circumstances, near instantaneous duplication of a file.”

“Obviously Apple proceeded slowly to implement APFS. Last year’s developer version could be installed on Macs with SSDs, but it didn’t support traditional hard drives nor that combo of HDD and SSD, the Fusion drive. I sort of expected it would be fully implemented with Sierra’s successor, but that’s still a work in progress,” Steinberg writes. “”

“With the first macOS High Sierra betas, Apple did provide the choice of converting Fusion drives, but put that to a halt when people ran into troubles. Unfortunately switching back to HFS+ involves invoking some Terminal commands, provided by Apple in a support document to public beta testers, and a full backup, erase and restore,” Steinberg writes. “With the final release of High Sierra, you didn’t have a choice on an SSD. It was automatically convered for better or worse. A regular hard drive can be converted manually in Disk Utility, and I did that on two external drives with mixed results.”

Much more in the full article here.

MacDailyNews Take: First backup – seriously, backup first – then proceed with caution.

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. As I’ve been ranting lately:
    Apple took over a DECADE to develop a replacement for HFS+. And they STILL aren’t finished! And yet they let loose what amounts to an UNfinished file format standard on Mac users.

    • Apple waited to provide developers with the ‘final’ standard until the day of High Sierra’s release. Therefore, there are NO compatible third party file system repair utilities at this time. This is the prime reason I’m waiting to upgrade.

    • APFS is still Fusion Drive illiterate. That’s [expletives hidden] crazy.

    I’m glad Gene Steinburg relented and wrote this second article about upgrading to High Sierra. His first article on the subject was, IMHO, detrimental. Humph.

    From a security point of view, now that Apple has patched the Keychain password leak for at least High Sierra, it’s very useful to upgrade. The Keychain password leak exists in ALL versions of macOS (not just High Sierra). There are plenty of other security patches in High Sierra as well.

    It’s up to the user to decide when to upgrade. And for users with SSD drives, the upgrade is likely to go well. But for those with Fusion Drives, forget about! And as Gene is pointing out, be wary if you’re upgrading a regular old spinning hard drive. There are concerns to consider.

    The usual OS PRE-upgrade/update strategy:

    1) Make A Backup!
    You should be doing that regularly anyway, unless you like living dangerously. Keep local backups and off-site backups, such as to the cloud.

    2) Repair your boot drive!
    This should also be done regularly in any case. I do it at least once a month. As such, I always (ALWAYS!) find problems on my SSD boot drive. Just before an OS update or upgrade is the perfect time to do a repair.

    Now we wait for Apple to really finish APFS. *Grumble*Grumble* 😛

  2. Given that Apple removed (!) the basic functionality of Podcasts playing in sequence in iOS11 (you have to manually play each episode or add them to a playlist in clunky fashion), I’m not looking forward to the hidden “surprises” of broken or lost features in High Sierra. Maybe Apple will surprise me and bring back Coverflow when attaching files to emails?

  3. Good advice – I totally screwed one of my my backup drives due to incompatibilities with Apple File System, and a lot of pro apps can’t read it yet. Once it’s fully implemented, I have no doubt APFS will be awesome, but for, now pros just shouldn’t upgrade, there is no way to prevent your disks from being converted to the new format.

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