Keep in mind that this is essentially 2 RAID0 arrays in tandem, meaning it only takes one disk to fail to loose all data! Use mirror as mentioned below so failure is one disk per Fusion Drive set and backup using Time Machine or move critical data onto cloud/NAS storage! Personally I’m running a RAID0 Stripe and depending upon TimeMachine as all critical data is saved to an Owncloud instance (for maximum speed).
- 2x Samsung 850 Pro SSDs
- 2x Seagate 7200RPM HDDs
So how do we combine all of these for one monster drive? Fusion Drive + RAID! Yes, you can even boot off of this.
First, get some paper and write down your disk mappings. Mine were:
- /dev/disk0 – 850 Pro
- /dev/disk1 – 850 Pro
- /dev/disk2 – Seagate 1TB HDD
- /dev/disk3 – Seagate 1TB HDD
Next we will create two fusion drives, one for each HDD/SDD set.
diskutil coreStorage create FUSE1 /dev/disk0 /dev/disk2
*Copy the UUID for the next command*
diskutil coreStorage createVolume S87D6F8F-D9WJ-8AD9-SD(UUID) jhfs+ "Macintosh HD1" 100%
Then repeat the steps for your 2nd Fusion Drive set.
Once done, do another diskutil list and write down your Fusion Drive mappings. In my case they were:
- /dev/disk18 – FUSE1
- /dev/disk19 – FUSE2
Next we will create a RAID0 across both Fusion drives. You are free to use whatever RAID level you want such as RAID 1 = “mirror”
diskutil appleRAID create stripe "Macintosh HD" JHFS+ disk18 disk19
If any of the above commands fail, press “up” in the terminal and run them again, some I had to due twice due to disks not unmounting the first time but the second time it worked!
Now you can install OS X to the drive. When doing a hackintosh, use Clover Configurator to copy your EFI folder to the first disk’s EFI partition (or do a diskutil list and pick a physical disk as your EFI boot drive). Be sure to set your BIOS to boot from the drive and all should be rosy!
And before you ask, creating fusion drives on RAID sets (the other way around) doesn’t work and leads to Kernel Panics so RAID on 2x Fusion Drives is the only way to go!