Clean Install High Sierra on APFS-formatted main HD
- From 10.11 or 10.12 systems, format an external hard drive with at least 500gb with "Mac Os Extended Journaled".
- Download High Sierra Beta and install it in the external hard drive.
- When the system reboots and finishes installation, it will boot from the external HD.
Go to Preferences and change
Startup Diskto be main HD.
- Reboot and press
Optionkey when the computer makes a beep and select external HD to boot from it.
- Once booted again into external HD, format main HD to be APFS.