How to Install a Fusion Drive into a Mac mini Running Mavericks

In order to speed up my computer without the expense of a large SSD, I just finished installing a DIY Fusion Drive into my 2011 Mac mini with great success. (This should work for Yosemite as well with minor modifications). I didn't expect the need to write about it but there were enough lessons and deviations that I'll describe them. Originally the Fusion Drive was released using Mountain Lion so most write-ups have not been updated for the newer OS X Mavericks. 

Update 10/24/2019: See also my post about setting up a proper recovery partition and fixing macOS installation errors.

Assumptions: You have a working 2011 Mac mini running OS X Mavericks with a single HDD and want to install a second drive (an SSD) internally to make a Fusion Drive.

First, the hardware, which I ordered all from Amazon. I chose:

• Mac mini dual drive kit from iFixit ($30) because I liked the included tools better than the similar kit from OWC (note: if prices are wonky, just order from the manufacturer directly or choose the other brand)

• Samsung 840 EVO 120GB SSD, because it was on sale and had good reviews
• That drive is now discontinued, so you might consider the Samsung 850 EVO

To install the second drive into the Mac mini I followed the very nice instructions from iFixit. While there were some whiners in the comments, I found the process to be totally achievable and the pictures and instructions to be great. Just read carefully and be patient to avoid the reported cursing and broken logic boards.

In the middle of the dual drive install -- everything has been removed from the Mac mini and the SSD is ready to go in

On the software side, I generally followed this procedure from OWC which is great but I have some simplifications and comments for using it with Mavericks:

• A Time Machine backup is all you need. It is not necessary to use CCC to clone your hard drive or anything like that. This step is fast if you are already backed up.

• To create the bootable OS X install drive, first download the installer from the App Store by going to the entry for Mavericks and pressing the "Download" button (I had to download twice because the first download was corrupted for some reason -- just re-download if you get any errors in the next step in the Terminal). Then follow this new procedure to make a bootable drive (very thorough article for one terminal command...). The old methods described in the OWC article steps 2-6 won't work.

• OK short version: if the Mavericks installer is in your Applications folder and there is a Mac OS X Extended (Journaled)-formatted volume named "Untitled" mounted, create the Mavericks install drive in the Terminal with:

sudo /Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ Mavericks.app --nointeraction

• After following the steps to create the Fusion Drive, there is no need to install a new copy of OS X or fiddle with Migration Assistant! Simply restore from your Time Machine backup while still booted from your install drive! Very simple.

After that it booted back into my system and it all worked like a charm. Much faster application launches and file copies. I would have saved many hours of file copies/OS installs with these steps so I hope you find this before embarking on your own project!

-Mike