Partitioning a Mac Hard Drive: A Step-by-Step Guide

If you're testing a beta version of macOS, you'll first install whatever the current version is. You may have to install an older version of macOS before updating it to the more recent version you want to run. This will install the latest available macOS onto the partitioned hard drive. This will take you to the Startup Manager and you can select your drive from there. You can also restart your Mac and press the Option Key when you hear the startup chime, allowing you to switch between OSes using the Startup Disk option.

Creating a separate volume on your Mac allows you to install a completely different operating system without having to change anything on your daily driver. If your Mac uses APFS, Apple recommends creating a volume instead of a partition. You can manually select size limiters for a volume if you're worried about one drive overtaking another's space.

One of the benefits of creating a separate volume is that it allows the volume to grow or shrink in storage size as needed. This means you don't have to worry about running out of temporary space while installing macOS, for example, because it will grab the necessary space from your main drive and then put it back when it's done.

But what exactly is an APFS volume? In simple terms, an APFS volume creates a similar container to be used the same way as a partition, but it mounts it within your main hard drive. If your Mac uses APFS, Apple recommends creating a volume instead of a partition.

On the other hand, if you're running a Mac using HFS+ file system (prior to macOS Catalina), you must partition your hard drive. However, if you're running low on storage capacity on your hard drive, it's not recommended to partition. Each partition will take up a portion of your usable storage, and it's important to note that partitioning your hard drive also splits up your available hard drive space.

It's worth noting that if you want to run Windows on your Mac, Apple's Boot Camp assistant will automatically make a partition for you. This makes it possible to run two separate operating systems on one device, like Windows and macOS, or two versions of macOS (like Catalina and Big Sur).

In summary, partitioning your Mac is basically splitting your hard drive into separate, usable systems. By following these simple steps, you can create a separate volume or partition your hard drive, giving you the flexibility to run multiple operating systems on one device.

Partitioning mac hard drive