RAID 0 is a popular disk setup solution to achieve the fastest possible read and write disk speeds by splitting data between two or more hard drives. The latest version of Mac OS X High Sierra (10.13) does not allow you to simply install to any kind of RAID configuration. This has frustrated a lot of the Mac community.
In order to install the latest version of Mac OS X onto a RAID 0 slice, you must clone a copy of your Mac OS X installation straight to the RAID 0 drives (not a restore, such as Time Machine, which will not work). To accomplish this, you need an external hard drive and a copy of SuperDuper software in addition to your RAID 0 drives.
We will use the same Mac machine (that will use RAID 0) to perform all the steps below. This method uses hardware RAID and is not a software RAID. In addition, you will be able to install updates from the App Store normally using this method.
Note: We strongly recommend taking a full backup (Time Machine) to another drive just in case when performing these steps! Save yourself from an accident!
- Use SuperDuper to clone your existing copy of Mac OS to the external drive. If you want to a fresh copy of Mac OS High Sierra instead, clone a copy of a fresh install of High Sierra to the external drive using SuperDuper.
Note: Be sure to complete your SuperDuper clones on the same type of Mac you will install the RAID 0 configuration on. This is important because your Mac OS High Sierra clone will have drivers and system files specific to that machines hardware.
- Next, boot from the cloned external drive we created. Plug in the drive and hold down the option key and choose the external drive install media.
- Now that we booted up from our external hard drive, we can manage our Mac’s internal hard drives and create our RAID 0 array. Remember to only create a RAID 0 array with the same model and capacity size drives.
Open Disk Utility in Applications -> Utilities and create your RAID 0 array shown below.
Go to File -> RAID Assistant
Select Striped (RAID 0)
Select your 2 internal hard drives to create the RAID array from
Name your single RAID drive. For Chunk size, choose a lower size if you will be using the RAID for regular needs (email/browsing/word processing.) For video editing, choose a higher chunk size.
Success screen appears
- Open SuperDuper and copy the external drive to your new RAID 0 drive.
The copy will complete successfully. Finally, go to System Preferences -> Startup Disk and select your new drive and restart. The first restart may take a little time as your boot files load for the first time.
You can confirm your successful RAID 0 in Disk Utility.