To install Big Sur and keep the data intact, select Install macOS Big Sur. Now, your Mac will boot into Recovery mode, and a window with four options will appear. When the Startup Manager appears, select your external drive. We are now very close to downgrading from macOS 12 beta to macOS 11 Big Sur. Once you created the bootable macOS Big Sur installer drive, you can boot your Mac from it with ease. How to Boot macOS Big Sur from the USB Installer Drive # You can also use the Terminal to create the macOS Big Sur ISO file if you want. In the end, you will see a message saying your drive is ready for use in the Terminal. The whole process may take several minutes.

Terminal will purge your USB drive and then copy the Big Sur installer file to your drive. Now, an alert may appear saying, “Terminal would like to access files on a removable volume.” Click on “OK” in the pop-up window. You need to type “Y” and hit Return to proceed. Terminal may warn you that your external USB drive will be erased. If asked, enter your system password and hit Return. Make sure to change “Drive” to the name of your USB drive. Next, paste the copied code in Terminal on your Mac. Now, select and copy the following command: You can use Spotlight to launch it quickly. Then, launch Terminal (Applications -> Utilities -> Terminal) app. You can change “Drive” to the name of your drive for ease of use. It’s with noting that in this guide, I have used “Drive” as the name of the external drive. To get started, connect the US drive to your Mac. So, even if you aren’t quite familiar with it, you can get the job done with ease. The Terminal makes it easy to make an external drive a bootable macOS installer. Use Terminal to Make a Bootable macOS Big Sur Drive # Then, head over to the Applications folder to check the “Install macOS Big Sur” app, which you can use to make the bootable drive. You can quit the installer by pressing the Command+Q shortcut. Click on the “Download” button to start downloading the macOS Big Sur installer software.Īfter the download is complete and the installer launches, make sure not to click on the Continue button.

Next, the Software Update system preference will open. Download macOS Big Sur Installer Software #Īnother essential requirement is the macOS Big Sur installer software that you can download from the Mac App Store. Use the table below to learn how to create a bootable macOS Big Sur USB install drive. You can get it done in the Disk Utility app located in the Applications -> Utilities folder. How to Create a Bootable macOS Big Sur USB Install Drive (2021) #īe warned that you will need to erase your drive and format it to Mac OS Extended (Journaled).

Use disk utility to erase your mac