Apple removed support for APFS for the Fusion Drive, which will create additional difficulties for some of the beta testers
As you know, in the operating system macOS appeared High Sierra file system, Apple File System (APFS), of which a first copertina told last year.
It should bring increased performance and reliability, and offer new solutions to security.
As it turned out, for a specific part of the user implementation of the APFS will be useless, and for some and does turn into unnecessary problems. The fact that in the final version of macOS High Sierra, which will be available September 25, the new file system will only work with solid state drives.
That is, for a large number of PC owners Mac equipped with HDD or Fusion Drive, APFS will be unavailable. Such PC will continue to use HFS+. However, the beta version of macOS High Sierra is allowed to use APFS on systems with Fusion Drive. And those Mac owners who took advantage of this opportunity, with the release of the final version of the new OS will have to spend a number of not the easiest manipulations to return to HFS+.
The list includes 11 actions, including the creation of backup through Time Machine, create an installer on an external drive using createInstallMedia and reinstalling the operating system.
However, Apple notes that may in the future add support for APFS for PC with Fusion Drive.