APFS changes affect Time Machine in macOS Big Sur, encrypted drives in iOS 14

Apple is increasing its support for APFS on its computing platforms, bringing the ability to use Time Machine with an APFS-formatted disk to macOS Big Sur, while enabling the ability to view external drives using encrypted APFS in iOS and iPadOS 14.

Introduced in 2016, APFS is Apple's forward-thinking file system that it uses across practically its entire device ecosystem. With the introduction of macOS Big Sur, iOS 14, and iPadOS 14, Apple will be making it even more useful for users, by adding support for APFS in a few new areas.

On macOS Big Sur, Apple is finally bringing the ability to use an APFS-formatted drive with Time Machine, 9to5Mac reports. With macOS Catalina and earlier releases, users were able to back up to an HFS+-formatted disk but not an APFS-formatted version, with macOS offering to reformat the drive to HFS+.

Under Big Sur, users will be able to back up directly to an APFS-formatted drive, eliminating the need to reformat any disks.

Encrypted Drives in iOS 14

For iOS 14 and iPadOS 14, Apple has plugged a hole for external drive support for one specific use case: APFS encrypted drives. While it is currently possible to view external drives in a number of common formats from an iPhone or iPad, it only works for non-encrypted drives, with encrypted drives being unreadable by the mobile devices.

On connecting an encrypted APFS drive to iOS 14 or iPadOS 14, the drive will appear on the updated Sidebar, with a selection of the drive bringing up a password prompt to decrypt it.

The added support for encrypted drives will only work for APFS-formatted drives, which may still be a limiting factor for some users in a multi-platform environment.

12 Comments

zeroID 13 comments · 4 Years

About 4 years ago

This is what I wish, but....

Is this valid also for encrypted DMG sparsbundle containers, or only for physical disks ???
An encrypted DMG sparsbundle container is a drive in macOS, is this valid also for iOS & iPadOS?

rob53 3307 comments · 13 Years

What about formatting external RAID HDD as APFS? OWC’s SoftRaid is waiting for Big Sur to make this happen. My RAID can’t be used to backup my Catalina APFS volumes.

neilm 1000 comments · 16 Years

So unless Apple has re-engineered Time Machine, they presumably must have updated APFS to support hard links. Anyone know?

JamesBrickley 104 comments · 8 Years

rob53 said:

What about formatting external RAID HDD as APFS? OWC’s SoftRaid is waiting for Big Sur to make this happen. My RAID can’t be used to backup my Catalina APFS volumes.

You do not need to format your NAS as APFS. But you need to setup something to act like an Apple Time Capsule. For example, my ZFS NAS has a tiny virtual machine running Linux that simulates the Apple Time Capsule. When I create a backup using the Apple Time Capsule it creates a DMG sparse image for each Mac. When doing so from a Big Sur Beta test Mac it creates the DMG sparse disk using AFPS. If I encrypt that image it still works. This is how off-the-shelf NAS providers like Synology work. They run the open source tools to simulate a Time Capsule over SMB (Netatalk).

You can do this without a Time Capsule emulation but it's a bit harder and requires you enable Time Machine over SMB on each Mac which is officially unsupported. It does in fact work. Here is the override. But I don't recommend this method.

defaults write com.apple.systempreferences TMShowUnsupportedNetworkVolumes 1

The supported method is if you were to run say a Mac mini with macOS High Sierra or above you could do it that way. Just mount the NAS storage on the Mac mini and turn on File Sharing select the mounted NAS folder and right-click it select Advanced Options and check the box to enable Time Machine network location. It will provide the intermediate Time Capsule like functionality and it will be fully supported by Apple. You don't even need macOS Server. It's quite a bit overkill in overhead and cost considering you can do the same with even an old Raspberry Pi and Netatalk open source project for far less and with far less overhead. Heck you could run quite a bit more on a Raspberry Pi 3+ and not even stress it much. Like a print server and a Pi-Hole (network wide ad-blocker), etc. But you could probably find alternative uses for the Mac mini to do many more things as well.

Remember that Mac's are still UNIX and they play extremely well with UNIX/Linux and when there is a will there is a way. You don't need to do everything with Apple. But Apple still makes things rather easy, you just need to know how to peel back the layers to find it at times. Bet most people didn't know that macOS High Sierra can run a Time Machine server. I just checked it's still an option.