How to Revert a drive from APFS back to HFS+

Apple’s new APFS (Apple File System) format is the default format for storage under macOS 10.14 Mojave, replacing the dependable and long-lived HFS+ format. However, there are still some instances where HFS+ needs to be used. For example, APFS is incompatible with Apple’s Time Machine backup application and FileVault 2 (which is used to encrypt full drives), and cannot be used to format Fusion drives — those drives that use a combination of a solid-state drive and conventional hard disk drive. What if you accidentally format a drive in the APFS format and then realize you can’t use Time Machine or FileVault 2? I recently ran into this dilemma when I formatted an external drive in the APFS format and it was unusable by Time Machine. In this tech tip, I’ll show you how to revert back to HFS+.

You can’t just use Disk Utility to reformat an APFS disk to HFS+ — once it has been converted to APFS, the only options that appear for erasing an APFS disk are to reformat in APFS. The method I’m showing here requires some familiarity with the Terminal application, which can be found in /Applications/Utilities.

Deleting the APFS Partition
Launch the Terminal app, type the following command at the prompt to locate the Physical Store identifier of the APFS partition, and press Return:

diskutil list

(The result of running 'diskutil list' in Terminal)

(The result of running ‘diskutil list’ in Terminal)

I have quite a few disks both in and attached to this iMac, so there’s a long list as seen in the screenshot above. The important thing is to find the drive we wish to revert to HFS+. In this case, it’s the drive listed at the bottom. It is listed as an APFS Volume with a name of ‘OWC Mercury Elite Pro mini‘ and a physical store reference of disk5s2

What I want to do now is destroy the APFS partition. This can be a bit dicey if you have data stored on the drive, in which case you will need to back up the data to another drive. To do this, we’ll type the following command:

diskutil apfs deleteContainer /dev/disk5s2

If you’re following these instructions, you’ll need to replace disk5s2 with the correct identifier for your drive.

(Running the diskutili apfs deleteContainer command in Terminal initializes the drive as HFS+)

(Running the diskutili apfs deleteContainer command in Terminal initializes the drive as HFS+)

By default, the drive is wiped as an APFS disk, then initialized as a case-insensitive HFS+ volume with the name ‘Untitled’. If you wish to change the name back to something more recognizable, such as ‘OWC Mercury Elite Pro mini’, that can be done in one of two ways:

1) In a Finder window, locate the drive ‘Untitled’, right-click on it, and select “Rename ‘Untitled'” (see screenshot below). Type in the new name, then press Return.

(Renaming the 'Untitled' drive in Finder)

(Renaming the ‘Untitled’ drive in Finder)

2) In Disk Utility, click on the drive ‘Untitled’ to select it in the left sidebar, then click the Erase button at the top of the window. Type in the new name for the drive (in this case, ‘OWC Mercury Elite Pro mini’), make sure that ‘MacOS Extended (Journaled)’ is selected as the format, and click Erase (see screenshot below).

(Using Disk Utility to rename a drive by erasing it)

(Using Disk Utility to rename a drive by erasing it)


The key thing to remember is that reverting to HFS+ from APFS is a destructive change — any data on the drive that you’re switching back to HFS+ will be fully erased. Be certain to back up any important data on the drive prior to attempting the change.

Read more on APFS at the Rocket Yard: 


LEAVE A COMMENT


  • OMG! This is amazing and thank you so much for posting this.




  • Thank you! You saved may day!




  • Paragon, an excellent company, have produced a free app which will convert APFS to HFS+ very simply and quickly.
    I have just used it on an external WD drive where I keep my iTunes library, connected to an Airport Extreme.




  • This won’t work with the main internal HD right? Also, how to check which format is being used on any drive?
    thank you!




  • My MacBook Air had no problem using a new esternal HD with AFPS with TM (maybe because the HD in the MacBook Air, being SSD, was converted to AFPS with Mojave)




    • Another superb, concise article from Rocket Yard. Thanks to all concerned. My external Thunderbolt 3 drive was anything but useful – being suddenly cluttered with apparently essential Mac inspired temporary files of the /private/var/folders/zz etc. etc. kind. A plethora of inaccurate warning messages led me to re-format to HFS+ (after finding this Rocket Yard post). Seems like 100% success so far – no more garbage so far. Many thanks again.




  • APFS is a deal breaker until Apple finishes it (yes, it is a beta yet) and releases full specifications, so that Alsoft can release DiskWarrior 6 to rebuild directory of APFS disks. And do not forget Time Machine 2 on such disks as well. By end 2019? Hopefully!




  • All of that terminal work is completely unnecessary. Mojave’s Disk Utility absolutely can reformat AFPS drives to HFS+ drives. From the View menu, select “Show all devices”. Then it’s a piece of cake to select the drive and reformat it.




  • Apple dropped the ball here. How sloppy it is that TM is incompatible with their new FS.




    • I have found people in IT profoundly lazy and not all that bright… Some are smart, for sure, yet one would think they would figure out this and the NeXT technology by now.

      I feel this technology is never really taught. Who wants to code all day?




  • A couple of points: First, older versions of Disk Utility (e.g. the version in Sierra) *can* reformat an APFS drive to HFS+. Second, Fusion drives most definitely can be formatted as APFS.




  • First, I’d like to thank any and all responsible for the Rocket Yard articles, I’ve benefitted from many.
    I recently upgraded from a failed 2010 21-inch iMac to a Late 2012 27-inch iMac. It’s an i7 with 3TB HD plus 128GB SSD, believe my, it’s an upgrade!
    When setting it up with the Mojave installer, I was able to use Disk Utility from the installer to format it as a 3.12TB APFS Fusion drive.
    After the install I mistakenly formatted my external 4TB drive APFS then, of course, it wouldn’t work for Time Machine. Again, using Disk Utility, I reformatted it Extended HFS+ so all is well.
    My concern is that my experience with both of these uses of Disk Utility seems to be at odds with the comments in this article.
    Thanks again for this excellent resource.