Apple's Federighi promises APFS boot support for Mac Fusion Drives 'very soon'

Apple will have news on APFS for the Fusion Drives in Macs "very soon," according to the company's software engineering head, Craig Federighi.

Fusion Drives combine conventional hard disks with a limited amount of flash storage, offering some of the benefits of both without the cost of a full-fledged SSD. The APFS file system was introduced alongside macOS High Sierra last year, and is optimized for flash storage, but Apple quickly revealed that Fusion Drives wouldn't be converted or be able to be used as boot drives.

"We intend to address this question very soon," Federighi said in an email exchange with a MacRumors reader.

Federighi's email is the first time that anyone inside Apple has addressed the issue.

APFS was first launched in beta for storage drives only shortly after the 2016 WWDC. Apple started the migration to APFS in devices with iOS 10.3.

Since Fusion Drive compatibility is missing in the macOS 10.13.5 beta, the executive's comments likely mean that Apple will announce support during WWDC 2018, scheduled to kick off June 4. That in turn would probably imply inclusion with this fall's macOS 10.14, given that the company rarely uses WWDC to talk about interim software updates.

APFS has become de facto on every Apple platform with flash storage, including not just Macs but iPhones, iPads, Apple TVs, and even the Apple Watch. Support for Fusion drives was included with early versions of the High Sierra beta for some models of Apple's fusion drive, but was completely stripped out during the testing process.

The format is a modern replacement for for the decades-old HFS+, with better efficiency, resiliency, and encryption, as well as easier backups.

24 Comments

MacPro 19838 comments · 18 Years

About 6 years ago

I am curious as to what Apple is fine tuning, anyone here know? The Disk Utility (Version 17.0 (1606)) that came with the first developer beta of High Sierra did and still does format anything you want as APFS including FusionDrives, HDD and RAIDs. I only played around with non essential drives and data obviously but never had a single problem.

Mike Wuerthele 6901 comments · 8 Years

MacPro said:

I am curious as to what Apple is fine tuning, anyone here know? The Disk Utility (Version 17.0 (1606)) that came with the first developer beta of High Sierra did and still does format anything you want as APFS including FusionDrives, HDD and RAIDs. I only played around with non essential drives and data obviously but never had a single problem.

You can format anything APFS. You just can't use spinning metal as a boot drive.

I've just clarified the language in the story a bit.

emoeller 588 comments · 17 Years

This is good news. My issues have been with DAS (direct access storage) units (such as the Akitio Thunder3 Quad Mini) whereby a drive sometimes disconnecst and the only way to reconnect them is to unplug either the power or the Thunderbolt3 cable (thus affecting all of the drive units). Neither Finder nor Disk Utility will allow reconnection via the operating system.

chabig 641 comments · 20 Years

Apple's Federighi promises APFS boot support for Mac Fusion Drives 'very soon'This headline couldn't be more wrong. Federighi said, "We intend to address this question very soon". All it means is that Apple will answer the question. It doesn't mean the answer will be affirmative.

foregoneconclusion 2836 comments · 12 Years

chabig said: This headline couldn't be more wrong. Federighi said, "We intend to address this question very soon". All it means is that Apple will answer the question. It doesn't mean the answer will be affirmative.

From what I've heard, APFS for the Fusion Drive had some issues in beta but not to the degree where you would think Apple wouldn't resolve them. I tend to doubt that Federighi would have responded like that if it wasn't going to be affirmative. Why would you tease a negative?