The instructions are a bit sparse, but should be sufficient for getting the job done. It covers two methods for converting a Fusion Drive back to HFS+ and installing macOS High Sierra. Warning: The process of creating the bootable installer will erase the contents of the selected drive volume.Īpple has posted instructions in its support area for Preparing Your Fusion Drive Mac for the macOS High Sierra Install. You’ll also need to create a bootable macOS High Sierra installer a 16 GB or larger USB flash drive or an external drive can serve this purpose. This can be an existing Time Machine drive as long as it’s formatted as HFS+.

You’ll need a drive partitioned as HFS+ for the Time Machine backup. Nevertheless, even if you decide to create a clone, we highly recommend you also create a Time Machine backup, especially if the clone is the only copy of your data you will have. It seems you should also be able to perform this task by creating a clone using Carbon Copy Cloner or one of the other popular cloning tools. Instead, you’re required to back up your current data with Time Machine, erase and reformat the affected drive(s), install macOS High Sierra, and then migrate your backed up data to the fresh install.Īpple includes instructions for the process, specifically using Time Machine as the backup app. Unfortunately, Apple isn’t providing any tools to revert the file system.

If you converted a Fusion drive during the beta, it needs to be reverted to HFS+ before you can install macOS High Sierra. Instead, it’s releasing macOS High Sierra with APFS only for Macs using SSDs (Solid State Drives). Apple backed away from its original goal of having APFS ready to go for all Mac configurations. If you’re a beta tester, you may have a slightly more difficult time upgrading than the rest of us it all depends on whether you installed the new APFS (Apple File System) during the beta testing. Note : Before upgrading to any new or updated operating system, it’s a good idea to have a current backup in place. With that in mind, here are some of the more common problems you may encounter when upgrading to macOS High Sierra. We’re always grateful that new versions of the operating system go through an extensive beta process, but it always seems a few issues will still be lurking, ready to pop up and surprise us. (macOS High Sierra’s initial install screen.)

It endured the summer beta program, and is now available through the Mac App Store for anyone to download and install. MacOS High Sierra is finally ready for release.

Reinstall macos sierra