There are all sorts of reasons why you may want to create a bootable macOS Big Sur USB install drive. For instance, if you often have to perform updates or clean install macOS on multiple Macs, having a bootable installer drive can make your task pretty straightforward. Not to mention, it can also help if you ever wish to downgrade from macOS 12 Monterey beta and go back to the stable macOS Big Sur version. With that said, let me show you how to create a macOS bootable installer drive.
- Download macOS Big Sur Installer Software
- Use Terminal to Make a Bootable macOS Big Sur Drive
- How to Boot from the Installer Drive
- Update the macOS Installer Drive
- Change Mac Security Setting to Use an External Startup Disk
Download macOS Big Sur Installer Software
Another essential requirement is the macOS Big Sur installer software that you can download from the Mac App Store.
- Launch the Mac App Store and search for macOS Big Sur.
After the download is complete and the installer launches, make sure not to click on the Continue button. You can quit the installer by pressing the Command+Q shortcut. Then, head over to the Applications folder to check the “Install macOS Big Sur” app, which you can use to make the bootable drive.
The Terminal makes it easy to make an external drive a bootable macOS installer. So, even if you aren’t quite familiar with it, you can get the job done with ease.
sudo /Applications/Install macOS Big Sur.app/Contents/Resources/createinstallmedia –volume /Volumes/Drive – /Applications/Install macOS Big Sur.app
- Next, paste the copied code in Terminal on your Mac. Make sure to change “Drive” to the name of your USB drive. Then, hit the Return key.
Once you created the bootable macOS Big Sur installer drive, you can boot your Mac from it with ease. We are now very close to downgrading from macOS 12 beta to macOS 11 Big Sur. Follow the steps below:
At times, you may need to update the installer drive to use it to clean install macOS Big Sur on your Mac machine.
- Connect your external drive and then restart your Mac and hold down the Option key while the Mac boots (when you see the Apple logo on the screen).
Change Mac Security Setting to Use an External Startup Disk
macOS comes with a security setting to disallow external startup disk. If it is enabled, you will need to change the security setting to allow booting from external USB or removable media drives.
- Next, an alert will show up saying, “Authentication Needed. You will need to authenticate as an Administrator to change the boot security settings.” Then, click on “Enter macOS Password“, and input the user name and password.
Well, that’s all there is to it! So, that’s how you can create and use a bootable macOS Big Sur USB install drive. The same process works for older-gen macOS versions as well. With a bootable USB install drive at your disposal, it becomes effortless to clean install macOS on your Mac machine. If you have to perform updates or clean install OS more often than not, this has to be the preferred way to go.
