
You are going to be utilizing this hard drive, Disk Utility and MaOS installer from the App Store. The faster the drive the better and a connection speed like Thunderbolt is preferred. In order to create another boot volume for your Mac, you will need a form of external storage such as a hard drive.

Here are the steps to create a bootable external volume to start up to on your Mac. How to Make a Bootable External Mac Hard Drive No matter the reason, having an additional bootable option on an external hard drive is definitely a good tool for any Mac user to have. Another is creating a drive for testing your Mac’s hardware. One of the main reasons is backup of your current system. There are quite a few reasons for why you may want to be able to have an additional startup drive for your Mac. Here is a guide on how to create a bootable external Mac hard drive to run macOS from an external hard drive.
