I thought this would be a fairly straightforward bit of Googling, but every other post I read gives contradictory information. Help!
I'm on an M4 MacBook Pro running Sequoia. The drive is a Seagate 5TB USB3 HDD (hard disk drive, aka spinning disk, aka not an SSD) to be used exclusively for Time Machine. Reliability and stability are priorities over speed.
Thanks for the advice!
EDIT: It appears this question is moot as modern Time Machine will convert the drive to APFS regardless of how it is originally formatted. Tested and confirmed.
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Note this answer now depends on the version of OSX/macOS you have.
This answer is for macOS Catalina and earlier versions - Big Sur now can use APFS - see Apple's Types of disks you can use with Time Machine on Mac You can also use HFS+ as before.
You can't use APFS as a Time Machine target:
https://support.apple.com/en-us/HT202784#format
Time Machine drives must be HFS+. That will likely change in the future but currently it is HFS+ only.
Now it can be done:
macOS 11.0 Big Sur: The Ars Technica review …in Big Sur, Time Machine does make the leap from using HFS+ to using APFS… https://arstechnica.com/gadgets/2020/11/macos-11-0-big-sur-the-ars-technica-review/9/
In addition to Kaizer Sozay's answer:
you do not have to make a backup on another machine. It's enough to put the following folders on the drive after formatting it with HFS+ (Mac OS Extended Journaled):
Backups.backupdb |__ SomeMachineName |__ 2022-07-30-060606
It's best to create this three nested directories/folders on your desktop first and copy it to your HFS+ TimeMachine drive in one go, because if you create a folder called Backups.backupdb on the root level of a drive, your Mac won't let you copy anything to or create in that folder.
These three folders are all it takes to convince Monterey that your drive is a valid TimeMachine volume and it will not reformat it with APFS when you add it to TimeMachine BigSur or Monterey.
IMHO it only makes sense to go through this effort for a spinning harddisk. If you use an SSD for TimeMachine, APFS is indeed the better choice.
- First find a machine running an earlier version of Mac OS prior to Big Sur.
- Format your SSD for HFS+ (Mac OS Extended etc)....
- Create time machine backup of this earlier OS.
- Then take the same drive to your Big Sur or later machine, and use the same drive to backup. This time, Time Machine will not wipe / format your drive as APFS because it will detect that there already is a Time Machine backup stored on the drive. As an added bonus, you can use the drive to store other files on it as well!
EDIT: Here is where its mentioned: https://support.apple.com/sq-al/guide/mac-help/mh15139/11.0/mac/11.0
The key thing is, the drive should already contain a time machine backup. If it does, then Time Machine won't wipe it / format to APFS, and will just continue with the previous format (Mac OS Extended)
I’m looking for possibly formatting my HDD to APFS. What performs better in day-to-day use?
APFS is very optimised for flash storage and I think it would performe worse than MacOS Extended on HDDs.
I just bought a new backup drive (WD MyPassport). It is formatted in HFS+.
Should I reformat it to APFS? All of the machines that will be backed up are running Big Sur, so Time Machine can use APFS or HFS+. I've read the APFS is slower than HFS+ on HDDs, but it is more reliable. So I'm leaning towards APFS. Which is best?