Build your own Fusion Drive with a hardwrk-kit and Mac OS X Mountain Lion

After this has been floating around the usual sites we have been getting quite exited about the possibility to have a Fusion Drive in any Mac without Apple’s hefty pricetag. Apple charges $250 for a Fusion Drive which includes a 128 GB SSD part. For this price you can have our adapter kit and a 128 GB SSD. Now you just need the newest OS X version and there you go.

Fusion Drive is implemented in the operating system, so it works within all Macs that are able to house more than one disk. We won’t brag that we have found out all of this ourselves, because we didn’t but before linking to other peoples work, we needed to find out if it all is working as advertised in a machine with a SSD / HDD combination in our kit. To get Fusion Drive to work in your MacBook, Mac Mini or iMac, you will need the following:

  • A Version of Mac OS 10.8.2 on a medium of your choice (Stick, USB drive, DVD)
  • An SSD & a HDD built into your Mac
  • An actual backup of your system & data

First of all you will need to boot your machine from the OS X image and enter Disk Utility. Now format both your drive in hfs+ format. After this exit Disk Utility and open Terminal. Here we are going to unify both drives into a core storage drive. This will be handled as a single Volume and OS X will treat it as a FusionDrive. To do this you will have to type in the following command:

diskutil cs create FusionDrive disk0 disk1

Fusion Drive is the name of our CoreStorage Device. You can use another name too (i.e. Macintosh HD as usual). disk0 and disk1 are the SSD & HDD. If you have more than two disks, those names may vary (i.e. disk03, disk04, etc.). Now you should get this reply from the Terminal:

Started CoreStorage operation 
Unmounting disk0
Repartitioning disk0
Unmounting disk
Creating the partition map
Rediscovering disk0
Adding disk0s2 to Logical Volume Group
Unmounting disk1
Repartitioning disk1
Unmounting disk
Creating the partition map
Rediscovering disk1
Adding disk1s2 to Logical Volume Group
Creating Core Storage Logical Volume Group
Switching disk0s2 to Core Storage
Switching disk0s2 to Core Storage
Waiting for Logical Volume Group to appear
Discovered new Logical Volume Group "96644C03-B64A-48F9-A8B3-09AA04577197"
Core Storage LVG UUID: 96644C03-B64A-48F9-A8B3-09AA04577197
Finished CoreStorage operation


To verify everything and see how the CoreStorage is setup, you now type this into the Terminal:

diskutil cs list

The reply should look like this:

 diskutil cs list CoreStorage logical volume groups (1 found)
+-- Logical Volume Group 96644C03-B64A-48F9-A8B3-09AA04577197
    Name:         FusionDrive
    Size:         620236955648 B (620.2 GB)
    Free Space:   7775502336 B (7.8 GB)
    +-< Physical Volume E4A05D39-7127-487C-A2D3-A7CE568A88EF
    |   ----------------------------------------------------
    |   Index:    0
    |   Disk:     disk1s2
    |   Status:   Online
    |   Size:     120988852224 B (121.0 GB)
    +-< Physical Volume F67F3FE9-6AB1-412C-8E65-02D099166834
    |   ----------------------------------------------------
    |   Index:    1
    |   Disk:     disk0s2
    |   Status:   Online
    |   Size:     499248103424 B (499.2 GB)

Now it’s time to set up the Logical Group Volume as our Fusion Drive disk. Therefore enter the following in Terminal:

diskutil coreStorage createVolume 96644C03-B64A-48F9-A8B3-09AA04577197 jhfs+ hardwrk 610g


The Number behind „createVolume“ represents the CoreStorage Logical Volume Group.  This needs to be the number displayed behind „Logical Volume Group“ in the step before. In our case it is „96644C03-B64A-48F9-A8B3-09AA04577197“. „jhfs+“ represents the filesystem (journaled hfs+), „hardwrk“ is the name of the disk which can be changed (i.e. Macintosh HD). Finally 610g determines the size (610 GB) of the partition we are going to create. This can be anything, but only up to the size of both your HDD and SSD combined. The Terminal now should reply the following:

Started CoreStorage operation 
Waiting for Logical Volume to appear
Formatting file system for Logical Volume
Initialized /dev/rdisk8 as a 610 GB HFS Plus volume with a 40960k journal
Mounting disk
Core Storage LV UUID: 6CBDCB9F-A08E-4E79-BDA7-69853BA24C1E
Core Storage disk: disk8
Finished CoreStorage operation


And this is it. Your Fusion Drive is ready and will work silently in the background! Now exit the Terminal and process with the installation of Mac OS X.

a) Do you need a Fusion Drive?

If you combine your HDD and SSD to a „Fusion Drive“ it’s just a big volume. It’s good if you are working mostly with large amounts of data (f.e. a big iPhoto library) and a dedicated SSD solution would be too expensive for you.

b) Do you need dedicated SSD speed?

Best if you need dedicated SSD Speed (fastest) and you’re mostly working with small files (and your HDD is mostly used for archives, music, watching movies,…)

Attention: we only do advise this to experienced users and at your own risk! Do always have a backup of your data at anytime!!! Our testing revealed that, as expected, a Fusion Drive is not as fast as running solely on an SSD. Anyways it is a great improvement to running on a HDD plus you can have large storage without worrying which programms or files to run from the SSD. To get a Fusion Drive or a regular SSD/HDD combination running in your MacBook, MacMini or iMac we recommend our SSD/HDD adapter-kit!