How to Boot Mac From USB
Booting your Mac from a USB drive can be incredibly useful in various scenarios. Whether you need to install a new operating system, troubleshoot your existing one, or recover data from a crashed system, booting from a USB drive provides you with the flexibility and control you need.
In this tutorial, we will guide you through the steps to boot your Mac from a USB drive.
- A Mac computer (Intel-based)
- A USB drive with sufficient storage capacity (at least 8GB)
- A bootable USB installation disk or recovery disk
Step 1: Prepare the Bootable USB Drive
Before you can boot your Mac from a USB drive, you need to create or obtain a bootable USB installation disk or recovery disk. There are several methods to do this depending on the specific purpose. Here are some common scenarios:
Creating a Bootable macOS Installation Disk:
- Visit the App Store and download the desired macOS version.
- Connect your USB drive to your Mac.
- Open Disk Utility (located in Applications > Utilities).
- Select your USB drive from the sidebar.
- Click on the “Erase” tab and choose “Mac OS Extended (Journaled)” as the format.
- Give your drive a name and click “Erase”. Note that this will erase all existing data on the drive.
- Once erased, open Terminal (located in Applications > Utilities).
- Type the following command: sudo /Applications/Install\ macOS\ [version].app/Contents/Resources/createinstallmedia –volume /Volumes/[USB Drive Name] –applicationpath /Applications/Install\ macOS\ [version].app
- Replace “[version]” with the specific macOS version you downloaded, and “[USB Drive Name]” with the name you gave your USB drive.
- Press Enter and authenticate using your administrator password.
- The process may take a while. Once done, your USB drive will be ready to boot your Mac.
Creating a Bootable macOS Recovery Disk:
- Ensure your Mac is connected to the internet.
- Click on the Apple menu and choose “Restart”.
- While restarting, hold down the Command (⌘) + R keys until the Apple logo appears.
- Select “Reinstall macOS” or “Reinstall OS X” and click “Continue”.
- Follow the on-screen instructions until you reach the “Install macOS” or “OS X Utilities” window.
- In the menu bar, click on “Utilities” and select “Disk Utility”.
- Select your USB drive from the sidebar and click on the “Erase” tab.
- Choose “Mac OS Extended (Journaled)” as the format, give it a name, and click “Erase”.Note that this will erase all existing data on the drive.
- Once erased, close Disk Utility and return to the “Install macOS” or “OS X Utilities” window.
- Click on “Reinstall macOS” or “Reinstall OS X” and follow the on-screen instructions to install the recovery system on your USB drive.
Step 2: Booting from USB
Now that you have a bootable USB drive, it’s time to boot your Mac from it. Here’s how:
- Connect the bootable USB drive to your Mac.
- While restarting, hold down the Option (⌥) key until you see the Startup Manager screen.
- You will see all available startup disks displayed. Use the arrow keys to select your USB drive.Note that it may appear as an external disk with an external icon.
- Once selected, press Enter or click on the upward-pointing arrow to start booting from the USB drive.Note that it may take a while for your Mac to load from the USB drive, so be patient.
That’s it! Your Mac should now be successfully booted from the USB drive, allowing you to perform the desired operations such as installing a new operating system, troubleshooting, or recovering data.
Remember to eject the USB drive when you are done to avoid booting from it again in the future.
Booting your Mac from a USB drive is a powerful technique that gives you control over your system’s functionality and allows you to perform a wide range of tasks. Whether you need to install a new operating system or recover data, following the steps outlined in this tutorial will help you achieve your goals.
Make sure to create a bootable USB drive beforehand and familiarize yourself with the Startup Manager screen for a smooth booting experience.