macOS Sierra Tidbits: Apple File System, RAID Support, and More

Apple yesterday announced macOS Sierra, the latest version of its Mac software platform and renamed successor to OS X El Capitan. The first beta was released to developers following yesterday's keynote, providing early adopters with a closer look at what's new.

Apple File System

Apple File System, or APFS, is a next-generation file system for Apple products based upon the iOS, macOS, tvOS, and watchOS software platforms, ranging from the Apple Watch to a Mac Pro.

macOS-Sierra-Apple-File-System
APFS, which supports nearly all of the features of HFS+, is optimized for Flash/SSD storage and features strong encryption, copy-on-write metadata, space sharing, cloning for files and directories, snapshots, fast directory sizing, atomic safe-save primitives, and improved file system fundamentals.

Apple has posted an Apple File System Guide on its Developer Portal with technical details and other documentation.

The file system is available in pre-release beta for Apple developers on macOS Sierra and is scheduled to ship in 2017.

RAID Support

RAID-Assistant-macOS-Sierra
Apple has reintroduced the ability to create and manage RAID volumes in Disk Utility on macOS Sierra, pleasing a number of Mac users who were left disappointed when the functionality disappeared in OS X El Capitan.

"Anywhere" Dropped From Gatekeeper

Apple has removed the Gatekeeper option to allow apps to be downloaded from "anywhere" by default in System Preferences > Security & Privacy, resulting in a warning dialog when you attempt to open an app from an unidentified developer. "Mac App Store" and "Mac App Store and identified developers" remain selectable.

Apps from unidentified developers can normally be opened by clicking the "Open Anyway" button in System Preferences > Security & Privacy, but the macOS Sierra release notes indicate that this button does not work in the first beta. A workaround solution is to hold down the Control key, click on an application, and choose "open."

Default Text Size in Notes

Notes-Default-Text-Size
Optimized Storage

macOS Sierra has a new optimized storage function that frees disk space on your Mac by automatically storing rarely used files in the cloud and keeping them available on demand. It can also help you find and remove old files you no longer use.

During its WWDC 2016 keynote, Apple briefly showed slides that indicate which types of files are stored or deleted.

iCloud-1
Old files that are backed up to iCloud include ePub books you've read, books in iBooks you've read, old screenshots, iTunes U courses you're not using, full-resolution photos, Mac App Store apps you're not using, old presentations, old PNGs and JPEGs, old RAW files, old text files, old word processing documents, old documents, languages you're not using, played iTunes podcasts, old home videos, fonts you're not using, old Mail attachments, old illustrations, movies in iTunes you've watched, dictionaries you're not using, viewed iTunes TV shows, iTunes songs you don't listen to, old clippings, old spreadsheets, and instructional system videos.

iCloud-2
Old files that can be found and removed include redundant Mail data, previous OS X installers, Apple Music playback caches, Safari web caches, cached iBooks animations, event logs, cached Map tiles, fault and error logs, iTunes inactive downloads, cached iBooks covers, trash after 30 days, Safari Web Cache, Configurator iOS files, Quick Look thumbnails, iTunes IPSW files, state dump logs, iBooks inactive downloads, archived Safari Reading List, persistent logs, Mac App Store inactive downloads, Xcode caches, old iPhone backups, Configurator inactive downloads, iTunes orphaned database temporary files, and TTL log files.

Siri Preferences

Siri
Share your own tidbits in our macOS Sierra: All The Little Things discussion thread.

Related Forum: macOS Sierra

Popular Stories

iphone 16 pro ghost hand

5 Reasons to Skip This Year's iPhone 17 Pro

Thursday July 10, 2025 4:54 am PDT by
Apple will launch its new iPhone 17 series in two months, and the iPhone 17 Pro models are expected to get a new design for the rear casing and the camera area. But more significant changes to the lineup are not expected until next year, when the iPhone 18 models arrive. If you're thinking of trading in your iPhone for this year's latest, consider the following features rumored to be coming...
apple wallet drivers license feature iPhone 15 pro

Apple Says iPhone Driver's Licenses Will Expand to These 8 U.S. States

Tuesday July 8, 2025 11:26 am PDT by
In select U.S. states, residents can add their driver's license or state ID to the Wallet app on the iPhone and Apple Watch, providing a convenient and contactless way to display proof of identity or age at select airports and businesses, and in select apps. Unfortunately, this feature continues to roll out very slowly since it was announced in 2021, with only nine U.S. states, Puerto Rico,...
macbook pro blue green

M5 MacBook Pro No Longer Coming in 2025

Thursday July 10, 2025 12:38 pm PDT by
Apple does not plan to refresh any Macs with updated M5 chips in 2025, according to Bloomberg's Mark Gurman. Updated MacBook Air and MacBook Pro models are now planned for the first half of 2026. Gurman previously said that Apple would debut the M5 MacBook Pro models in late 2025, but his newest report suggests that Apple is "considering" pushing them back to 2026. Apple is now said to be...
iPhone 17 Pro in Hand Feature Lowgo

Leaker Reveals Amount of RAM in iPhone 17 Through iPhone 17 Pro Max

Wednesday July 9, 2025 8:08 am PDT by
Three out of four iPhone 17 models will feature more RAM than the equivalent iPhone 16 models, according to a new leak that aligns with previous rumors. The all-new iPhone 17 Air, the iPhone 17 Pro, and the iPhone 17 Pro Max will each be equipped with 12GB of RAM, according to Fixed Focus Digital, an account with more than two million followers on Chinese social media platform Weibo. The...
iPhone 17 Pro in Hand Feature Lowgo

iPhone 17 Pro to Reverse iPhone X Design Decision

Monday July 7, 2025 9:46 am PDT by
Since the iPhone X in 2017, all of Apple's highest-end iPhone models have featured either stainless steel or titanium frames, but it has now been rumored that this design decision will be coming to an end with the iPhone 17 Pro models later this year. In a post on Chinese social media platform Weibo today, the account Instant Digital said that the iPhone 17 Pro models will have an aluminum...
apple tv 4k new orange

New Apple TV Expected Later This Year With These New Features

Saturday July 12, 2025 3:09 pm PDT by
A new Apple TV is expected to be released later this year, and a handful of new features and changes have been rumored for the device. Below, we recap what to expect from the next Apple TV, according to rumors. Rumors Faster Wi-Fi Support The next Apple TV will be equipped with Apple's own combined Wi-Fi and Bluetooth chip, according to Bloomberg's Mark Gurman. He said the chip supports ...
Foldable iPhone 2023 Feature 1

Foldable iPhone Display Production Begins Ahead of Launch Next Year

Wednesday July 9, 2025 10:59 pm PDT by
Production of foldable OLED displays for Apple's first foldable iPhone have begun ahead of its expected launch next year, Korea's ETNews reports. The first foldable iPhone's displays are being produced by Samsung Display, who are establishing a production line dedicated to the upcoming Apple device its A3 factory in Asan, Chungcheongnam-do. The production line will make displays exclusively...
iphone 16 pro pro max

iPhone 17 Pro Models With BOE Displays Will Be Sold in China Only

Thursday July 10, 2025 11:59 pm PDT by
iPhone 17 Pro and iPhone 17 Pro Max models with displays made by BOE will be sold exclusively in China, according to a new report. Last week, it emerged that Chinese display manufacturer BOE was aggressively ramping up its OLED production capacity for future iPhone models as part of a plan to recapture a major role in Apple's supply chain. Now, tech news aggregator Jukan Choi reports...

Top Rated Comments

SeaFox Avatar
119 months ago
Hmmm, I assume there will be an easy way to disable these "optimized storage" functions. I don't want stuff being uploaded to the cloud and removed from local copy on the OS's whims really.

Also, regarding that new synchronized Documents, etc folders, not sure if that's gonna work without Apple beefing up the free iCloud storage -- and I mean at least four fold.
Score: 40 Votes (Like | Disagree)
Markoth Avatar
119 months ago
Is it strange that the most exciting thing for me up there is Apple File System? This is seriously going to help fix a ton of the more... questionable parts of OS X erm... excuse me: macOS. Time Machine should benefit tremendously from filesystem-provided snapshots. Exciting times. :)
Score: 36 Votes (Like | Disagree)
Markoth Avatar
119 months ago
Can someone tell an average person like me the advantages of the new file system?? Thanks
Well, for one thing, your data should be a lot safer with this new filesystem. Also, the ability to clone files and directories will let you instantaneously make copies of files. Those copies will appear to be completely separate files, but thanks to this new filesystem, the copy won't take up any additional space until you actually make edits, and even then, the space taken should be roughly equal to the space of the edits you made, and not the entire file. This is a huge win for many workflows.

Snapshots will allow for time machine to operate much more efficiently. Assuming the snapshots work as they do on other filesystems, it will allow Time Machine to basically tell the filesystem to "remember the data as it is now", without taking any additional space until data is added or modified. This will be a much better way to implement snapshots than the current method..

Fast directory sizing will allow OS X to compute the size of the data in a folder MUCH faster! As many of us know, large folders can take OS X awhile to compute... Always been a pet peeve of mine. :)

There are other great additions, but these are the ones I thought I could explain simply. Hope I did a decent job... :)
Score: 32 Votes (Like | Disagree)
Apple-Guy Avatar
119 months ago
Euhm.. could you like, not touch my files and move them elsewhere? Okay? Thanks.
Score: 31 Votes (Like | Disagree)
Markoth Avatar
119 months ago
Time machine backups not supported.

Incompatible with fusion drives.

Incompatible with startup disks.

Files cannot be used with FileVault.

Case-sensitive only file names.

But wait! Nano-second time stamping, and it works with your Apple Watch!

Remember if you synced your iPhone to a Windows device, you'd have to erase everything to format for PC use? Is this what will happen with files created under APFS?

"Send over that session!"

"Sorry, Patrick. You have to buy a new Mac to open it!"
They're not allowing it to do a whole lot, simply due to the fact that this is a very early version, and the filesystem is a very fundamental part of an OS. Beta filesystems are never fun to use (especially as a boot partition), and I'm betting this is no exception. Apple is smart playing it safe, especially given the wave of users coming in July to the beta.
Score: 23 Votes (Like | Disagree)
Jacquesvw Avatar
119 months ago
.
Score: 17 Votes (Like | Disagree)