Apple’s Disk Utility is usually the go-to app for reformatting, partitioning, and diagnosing storage devices on your Mac. For many years, the Disk Utility app stayed the same in terms of features and user interface. But that changed with OS X El Capitan; Disk Utility got a major facelift, and it also had its feature set modified. One of the major changes was that Apple removed any ability to set up and configure a redundant array of independent disks (RAID). You had to turn to a third-party app to do so.
In macOS Sierra’s Disk Utility (version 16.0, if you’re keeping track), the RAID features are back. At least they’re back in the macos Sierra Public Beta. There’s always a chance that Apple will pull the RAID features in subsequent releases, but there’s a good chance they’re here to stay. This article will be updated as beta updates are released, as well as when Sierra is officially released in the fall.
Here’s how to set up and configure a software RAID using macOS Sierra’s Disk Utility. You can use Disk Utility if you, say, bought a multi-bay drive chassis and have filled it with spare hard drive mechanisms you had sitting in storage. Or you already have a RAID array and need to reconfigure it.
(In case you’re wondering, a software RAID is one where the Mac manages the RAID. A hardware RAID is a RAID array that includes a separate computer that manages the RAID. Learn more about hardware RAIDs. If you’re new to software RAIDs, here’s how to get started with the storage devices, then come back to this article to set up the RAID.)
How to set up a RAID in macOS Sierra’s Disk Utility
This will erase any data that exists on the disks you want to use for the RAID. Back up that data if you want to save it.
After you connect your storage devices to your Mac, launch Disk Utility. It’s located in the Utilities folder, which resides in your Applications folder. You can also press Shift-Command-U or select the Go > Utilities menu while in the Finder.
With Disk Utility open, you should see the main window. To get to the RAID tools, click on the File menu and select RAID Assistant.
How to access the RAID Assistant in macOS Sierra’s Disk Utility.
On the opening screen of the RAID Assistant, you select the RAID type. Which one should you choose?
(Striped) RAID 0: This one’s all about speed. It doesn’t offer data protection, so you’ll need to rely on another backup system, like Time Machine. But if backup isn’t an issue and you need the performance, go with RAID 0.
- (Mirrored) RAID 1: The same data is written to all the drives. If a drive fails, your data is intact. When your Mac needs to read a file, the performance is faster because the data can be read by multiple drives.
- Concatenated (JBOD): This simply takes your drives and uses them to create one storage volume. It doesn’t offer data protection or better speed.
Sign up for Computerworld eNewsletters.