How to Partition Your Mac Hard Drive for macOS Beta

A good way to keep your data separate is to partition your Mac’s hard drive. A partition divides your storage into two spaces, like putting a trunk divider in your car. The most common use case is to install a second operating system on the same computer. In college I had a separate partition so I could boot into Ubuntu and a third partition with Windows. With today’s Macs running Apple Silicon, there is no easy way to natively install Windows or Linux…again.
But you’re probably here so you can install the macOS 13 beta. The developer beta is slated for the first week of June during WWDC22, Apple’s annual developer conference. The smart way to install it — above all with developer betas, which can be notoriously rocky – is to use a separate partition.
The Mac comes with a very handy tool to partition your hard drive for free. Read on to partition your hard drive with Disk Utility.
How to Partition Your Mac Hard Drive
First, open disk utility. Search for it using Spotlight (⌘ Space) or find it in Apps > Utilities.
Screenshot: D. Griffin Jones/Cult of Mac
On the left, you’ll see a sidebar with internal storage and external storage (any hard drives or USB sticks plugged in).
Click the arrow (❯) next to the top item listed under Internal (mine is titled APPLE SSD, yours may vary). Select Container disk1.
Screenshot: D. Griffin Jones/Cult of Mac
In the toolbar, click the +Volume button. This will add another partition, but it will share space with your primary hard drive.
Enter a name. I’m writing this article in May, so I don’t know what the next version of macOS will be called; I named the partition Thirteen. (You can change the name at any time.)
With the default settings, you can just click To add and be done.
You don’t need to change the format. Leave it selected as APFS. The Apple File System (APFS) is what modern macOS is designed for. Unless you have a specific reason to choose Mac OS Extended or ExFAT for compatibility reasons, leave it as APFS.
You also don’t need to manually specify how much space to give to the new partition. Macs, unlike PCs, use a special file system that shares space between partitions on the same hard drive, dynamically allocating space as it is used.
Screenshot: D. Griffin Jones/Cult of Mac
Click on Size options… whether you want to set a minimum or maximum size.
Reserve size is the minimum, Quota size is the maximum. If you’re installing macOS on this partition, you’ll need at least 64 GB, especially if you’re using the beta for development. I would limit the available space to 128GB unless you have a 1TB or larger hard drive. Click on OKAY confirm and To add to create the partition.
And that’s all! Partitioning a hard drive is notoriously easy thanks to the Apple file system. And if it looks like your hard drive is almost full, check out our guide on how to free up storage space.