MacOS – Cannot install macOS Mojave on external spinning drive. Error: This Mac can only install macOS on APFS-formatted drives

disk-utilityexternal-diskmacmacosmojave

I am using the Install macOS Mojave.app installer on my Mac mini (2018) running Mojave 10.14.5 to install Mojave on a formatted external spinning disk laptop drive (a Toshiba model with case).

I successfully formatted the drive using Disk Utility app in the GUID format.

Now when running the Mojave installer, it refuses to install on the external drive saying:

This Mac can only install macOS on APFS-formatted drives.

But I thought APFS was intended only for solid-state drives, not spinning drives. And there was no APFS option in Disk Utility that I could see.

➥ Is it now impossible to install and boot on an external spinning drive?

Best Answer

You are almost there. Check again in Disk Utility app.

Format

You will find APFS as an option in the Format pop-up menu.

Scheme

You make the same choice of GUID Partition in the other pop-up menu Scheme.

Related Solutions

MacOS – External drive Mojave installs unaccessible from Mavericks

The simplest way to boot back to Mojave would be to reboot the Mac and immediately hold down the option key. This will invoke the Startup Manager. Select the Mojave startup disk. Next, click on the arrow below the icon to boot Mojave. If you wish to make Mojave the default, then hold down the control key before clicking on the arrow.

Apple a recently added new instructions for using the Startup Manager. These instructions can be found on the Apple website: How to select a different startup disk.

While it is technically possible to select Mojave directly from Mavericks, this would involve installing a third party boot manager such as rEFInd. Unless you intend to change operating systems often, such an installation would probably not be worth the trouble to pursue.

MacBook – Unable to format internal drive as APFS on 2018 MacBook Pro

Below are three examples of how to erase the drive and create a APFS volume named MyVolume. You only need to follow one of the examples.

The commands given below create a Mac OS Extended (Journaled) partition, then reformat to APFS.
```
diskutil eraseDisk JHFS+ dummy GPT disk0
diskutil apfs create disk0s2 MyVolume
```
The commands given below create a Mac OS Extended (Journaled) partition, then convert to APFS.
```
diskutil eraseDisk JHFS+ myVolume GPT disk0
diskutil apfs convert disk0s2
```

The commands given below create a Mac OS Extended (Journaled) partition, then convert to an empty APFS container. Finally an APFS volume is added to the container..

diskutil eraseDisk JHFS+ dummy GPT disk0
diskutil apfs createContainer disk0s2
Container=$(diskutil info disk0s2 | grep Container)
diskutil apfs addVolume "${Container##* }" APFS myVolume