New Apple File System Coming in macOS High Sierra Won't Work With Fusion Drives

When macOS High Sierra is released to the public next week, the new Apple File System (APFS) feature will be limited to Macs with all-flash built-in storage, which means it won't work with iMacs and Mac minis that include Fusion Drives.

Macs with Fusion Drives were converted to APFS during the beta testing process in the first macOS High Sierra beta, but support was removed in subsequent betas and not reimplemented.

With the release of the Golden Master version of the software, Apple has confirmed APFS will not be available for Fusion Drives and has provided instructions for converting from APFS back to the standard HFS+ format.


Public Beta testers who had a Mac with a Fusion Drive converted to APFS will need to follow a long list of instructions to convert back to HFS+, including making a Time Machine Backup, creating a bootable installer, and using Disk Utility to reformat their Macs and reinstall macOS High Sierra.

Apple on September 5 published a support document confirming compatibility. When customers with an all-flash machine upgrade to macOS High Sierra install the update next week, their drives will be converted to AFPS. Apple explicitly says "Fusion Drives and hard disk drives aren't converted."

Apple says APFS will not be supported on Fusion Drives "in the initial release of macOS High Sierra," which suggests support could be added for Fusion Drives at a later date after lingering bugs are worked out.

Apple File System is a more modern file system than HFS+ and is optimized for solid state drives. It is safe and secure, offering crash protection, safe document saves, stable snapshots, simplified backups, and strong native encryption.


It's also more responsive than HFS+ with features like instant file and directory cloning, fast directory sizing, high performance parallelized metadata operations, and sparse file writes.

Apple plans to release macOS High Sierra on Monday, September 25.

Top Rated Comments

(View all)
Avatar
35 months ago
Classic Tim Cook Apple...
Score: 58 Votes (Like | Disagree)
Avatar
35 months ago
That's going to cause some serious Fusion Confusion™.
Score: 53 Votes (Like | Disagree)
Avatar
35 months ago

Shame I thought they'd ironed these kinks out during the beta phase - they've had over a year now to get it work with Fusion Drives and hard drives.

Filesystems are one part of an OS where I really don't want the developers to rush, I want all the bugs thoroughly ironed out. Because that's where I keep all my stuff.
Score: 42 Votes (Like | Disagree)
Avatar
35 months ago
Apple have so lost the plot it's scary!
Score: 33 Votes (Like | Disagree)
Avatar
35 months ago
Yikes. Probably should have made that call before beta 1...
Score: 32 Votes (Like | Disagree)
Avatar
35 months ago
With every move Apple makes in the past couple of years, they are bringing me closer and closer to the day when I completely leave the ecosystem, both for computers and smartphones.
Score: 29 Votes (Like | Disagree)

Top Stories

Apple's First MacBook Pro With a Retina Display Will Become 'Obsolete' in 30 Days

Monday June 1, 2020 7:50 am PDT by
If you are still hanging on to a Mid 2012 model of the 15-inch MacBook Pro with a Retina display, and require a new battery or other repairs, be sure to book an appointment with a service provider as soon as possible. In an internal memo today, obtained by MacRumors, Apple has indicated that this particular MacBook Pro model will be marked as "obsolete" worldwide on June 30, 2020, just over...

Tim Cook Addresses George Floyd's Death and Ensuing Protests and Riots as Apple Temporarily Closes Some U.S. Stores

Sunday May 31, 2020 8:04 pm PDT by
Amid unrest in numerous U.S. cities following last week's killing of George Floyd by police in Minneapolis, Apple CEO Tim Cook has shared an internal memo with employees (via Bloomberg) addressing the pain that many are feeling and urging others to commit "to creating a better, more just world for everyone." Cook also announced that Apple is making donations to several groups challenging...

Apple Releases macOS Catalina 10.15.5 Supplemental Update With Security Fix

Monday June 1, 2020 10:56 am PDT by
Apple today released a supplemental update for macOS Catalina 10.15.5, the fifth update to the macOS Catalina operating system that was released in October 2019. The supplemental update comes a week after the release of the macOS Catalina 10.15.5 update. ‌macOS Catalina‌ 10.15.5 is a free update that can be downloaded from the Mac App Store using the Update feature in the System...

iOS 14 Again Said to Be Compatible With All iPhones Able to Run iOS 13

Monday June 1, 2020 2:08 pm PDT by
iOS 14 will be compatible with all iPhones and iPod touch models able to run iOS 13, according to information shared today by Israeli site The Verifier. The compatibility data was allegedly found in a leaked version of iOS 14 and confirmed by what The Verifier says is a "trusted source from the system development process." iOS 13 is compatible with the iPhone 6s and later, with a full...

Apple Releases iOS and iPadOS 13.5.1 With Fixes for Recent 'unc0ver' Jailbreak Vulnerability

Monday June 1, 2020 9:58 am PDT by
Apple today released iOS and iPadOS 13.5.1, minor updates that come a little over a week after the release of iOS and iPadOS 13.5, major updates that brought the Exposure Notification API, FaceTime changes, mask-related unlocking updates and more. The iOS and iPadOS 13.5.1 updates are available on all eligible devices over-the-air in the Settings app. To access the updates, go to Settings >...

Mockups Depict iPhone 12 Lineup Sizes, Relocated SIM Tray

Monday June 1, 2020 1:22 pm PDT by
A series of 3D printed iPhone 12 mockups designed based on leaked schematics and info from Apple's supply chain was today shared by Japanese site Mac Otakara, giving us a first look at what we can expect from the 2020 iPhone lineup. Rumors have suggested Apple will release four iPhone 12 models in 2020: A 5.4-inch iPhone 12, a 6.1-inch iPhone 12, a 6.1-inch iPhone 12 Pro, and a 6.7-inch...

Five Mac Apps Worth Checking Out - June 2020

Tuesday June 2, 2020 2:25 pm PDT by
Apps developed for the Mac often don't receive as much coverage as apps designed for iPhones and iPads, so we have a series at MacRumors that highlights interesting Mac apps that are worth taking a look at. This month's apps are designed to make working from home a little bit easier. Subscribe to the MacRumors YouTube channel for more videos. Meeter (Free) - Working from home often...

Apple Music Joins Music Industry's Blackout Tuesday Awareness Campaign

Tuesday June 2, 2020 1:31 am PDT by
Apple Music has cancelled its Beats 1 radio schedule for Blackout Tuesday and is suggesting that listeners tune in to a radio stream celebrating the best in black music. Blackout Tuesday is a campaign organized by the music industry to support Black Lives Matter after Minneapolis citizen George Floyd was killed by police in the course of his arrest. On launching Apple Music, many users...

6.1-inch 'iPhone 12' Production to Begin in July Ahead of Other 2020 Models

Monday June 1, 2020 2:36 am PDT by
Volume production of Apple's forthcoming 6.1-inch "iPhone 12" models will start in July-August ahead of the rest of the company's flagship iPhone lineup this year, according to a new report by DigiTimes. Apple is widely rumored to be launching four new ‌iPhone‌ models in the usual September or October timeframe, although supply constraints and delays in production ramp-up could cause a...

Apple Releases tvOS 13.4.6 for Fourth and Fifth-Generation Apple TV Models

Monday June 1, 2020 9:56 am PDT by
Apple today released tvOS 13.4.6, a minor update to the tvOS operating system that runs on the fourth and fifth-generation Apple TV models. tvOS 13.4.6 comes a little over a week after the release of tvOS 13.4.5. tvOS 13.4.6, a free update, can be downloaded over the air through the Settings app on the Apple TV by going to System > Software Update. Apple TV owners who have automatic software ...