Updated
September 05, 2016.
The Fusion drive on a Mac is made up of two physical drives: an SSD and a standard platter-based drive. A Fusion drive combines the best of both worlds; the wonderfully fast performance of the SSD and the delightfully large, and relatively cheap, storage space of a standard hard drive.
While the Fusion setup creates a nice performance boost for most Mac users, there may be a time when you no longer want the Fusion drive, and would prefer to have two distinctly separate drives for your Mac.
You may find that having separate drives is a better configuration for your data needs, or perhaps you just want to replace either the SSD or the hard drive with a larger or faster one. No matter the reason for doing it, separating the drives into their individual components is an easier task than Apple lets on.
Disk Utility Doesn't Come to the Rescue
Disk Utility doesn't completely support Apple's Core Storage technology, which is the system behind the scene that allows the Fusion drive to work. Yes, you can see your Fusion drive in Disk Utility, and you can erase its data, but Disk Utility lacks a way to split the Fusion drive into its basic components. Likewise, there is no way to create a Fusion drive in Disk Utility; instead, you have to resort to Terminal to set up a Fusion drive.
Of course, if you can create a Fusion drive in Terminal, you can split one up as well. That's the method we'll use in this guide to deleting a Fusion drive.
Using Terminal to Delete a Fusion Drive
The process of deleting a Fusion drive isn't very difficult; all it takes is three Terminal commands, and your Fusion drive will be split into its individual drives.
As a bonus, they will be reformatted and ready to use.
That's an important point to remember; deleting a Fusion drive destroys all data contained on the drives. This includes not only the normal system and user data you may have stored on them, but also any data on a hidden partition, such as the Recovery HD used for OS X Lion and later.
This is an advance DIY process so take your time and read through the entire process. And before you do anything, take the time to back up your data as well as copy your Recovery HD to a new location.
When you're ready, proceed to the next page to get started.
