WARNING A Fusion Drive is classed as a logical volume group in CoreStorage. Opening Terminal from the Utilities menu in macOS Recovery Mode Once started, open Terminal from the Utilities menu: Quit and then re-open Disk Utility to see the correct disk configuration:Īt this point you have a Fusion Drive formatted as HFS+ and can continue with the steps in the remainder of this article.Container disk 2 is deleted and the sidebar will show something similar to: At the prompt, enter Macintosh HD for the Name – it will likely be pre-populated with Preboot – and select Mac OS Extended (Journaled) for the Format.Select Container disk 2 in the sidebar and click the Erase icon in the toolbar.

The Mac’s startup Fusion Drive should be listed in the Disk Utility sidebar:ġ The disk identifier may be another number. In the top-left corner of Disk Utility, click the View dropdown and select Show All Devices.Having started your Mac in Recovery Mode, open Disk Utility.IMPORTANT: Performing these steps will erase all the data on your Fusion Drive. However, they are still relevant when running macOS Mojave with an APFS-formatted Fusion Drive providing you first perform these extra steps: The instructions detailed in this article are only applicable to HFS+ Fusion Drives. Since the release of Mojave, installing or updating macOS from an earlier version has forced startup Fusion Drives formatted as HFS+ to be automatically converted to APFS as part of the install process. Information for Fusion Drive Macs Running macOS Mojave (10.14)

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