how to create bootable macos usb drive

How to Create a Bootable macOS USB Drive: A Comprehensive Guide

Introduction

Creating a bootable macOS USB drive can be a lifesaver when you need to reinstall your operating system, recover lost data, or troubleshoot issues. Whether you’re a tech-savvy user or a complete beginner, this detailed guide will provide you with step-by-step instructions to set up a bootable macOS USB drive effortlessly.

Getting Started

Preparation:

• Gather the following: a USB drive (8GB or larger), a macOS installer (downloaded from the Apple website), and a Mac computer running macOS High Sierra or later.
• Format the USB drive in macOS Extended (Journaled) format using Disk Utility.

Creating the Bootable Drive:

• Launch Terminal (Applications > Utilities > Terminal).
• Type the following command and press enter:

sudo /Applications/Install macOS [version].app/Contents/Resources/createinstallmedia --volume /Volumes/[USB Drive Name] --applicationpath /Applications/Install macOS [version].app

• Replace [version] with the version of macOS you’re installing (e.g., Catalina) and [USB Drive Name] with the name of your USB drive.
• Enter your administrator password and press enter.

Using the Bootable Drive

Booting from the USB Drive:

• Insert the bootable USB drive into your Mac.
• Restart your Mac and hold down the Option key during startup.
• Select the USB drive as the boot device.

Installing macOS:

• Follow the onscreen prompts to install macOS on your computer.
• Once the installation is complete, you can remove the USB drive.

Troubleshooting

Common Issues:

• USB drive not recognized: Ensure the USB drive is formatted correctly and properly inserted.
• macOS installer not found: Check that you downloaded the correct installer file and specified the correct path in the Terminal command.
• Installation failed: Verify that your Mac meets the system requirements for the macOS version you’re installing.

Advanced Troubleshooting:

• UEFI boot: Use Startup Security Utility to toggle between UEFI and legacy boot modes.
• Boot flags: Modify the Terminal command to add boot flags for specific scenarios (e.g., -verbose for detailed logs).

Comparison of USB Drive Formatting Options

Format	Advantages	Disadvantages
macOS Extended (Journaled)	Compatible with both Intel and Apple Silicon Macs	Not always recognized by Windows
ExFAT	Cross-platform compatibility	Can result in data corruption on some Macs
HFS+	Optimized for older Macs	Not supported on Apple Silicon Macs

Conclusion

Mastering the ability to create a bootable macOS USB drive empowers you to handle various technical situations with confidence. By following the comprehensive steps outlined in this guide, you can ensure the successful installation or troubleshooting of macOS on your computer. Remember to carefully address any potential issues and choose the appropriate USB drive formatting option based on your specific needs.

FAQ about how to create bootable macOS USB drive

What is a bootable macOS USB drive?

A bootable macOS USB drive is a USB flash drive that contains a copy of the macOS installer. You can use it to install macOS on a new computer or to boot into macOS from a USB drive.

What are the requirements to create a bootable macOS USB drive?

You will need:

• A USB flash drive with at least 16GB of storage space
• A Mac running macOS Mojave or later
• An internet connection

How do I create a bootable macOS USB drive?

1. Format the USB drive. Connect the USB drive to your Mac and then open Disk Utility. Select the USB drive in the sidebar and click the Erase button. Choose Mac OS Extended (Journaled) as the format and then click the Erase button again.
2. Download the macOS installer. Open the App Store and search for macOS. Click the Get button to download the installer.
3. Create the bootable USB drive. Once the macOS installer has finished downloading, open the Applications folder and launch the Terminal app. Type the following command into the Terminal window and press Enter:

sudo /Applications/Install macOS Monterey.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install macOS Monterey.app

Enter your password when prompted.
4. Wait for the process to complete. The process of creating the bootable USB drive will take some time. Once it is complete, you will see a message that says "Install media creation complete" in the Terminal window.
5. Eject the USB drive. Once the bootable USB drive has been created, you can eject it from your Mac.

How do I install macOS from a bootable USB drive?

1. Insert the bootable USB drive into your Mac.
2. Restart your Mac.
3. Hold down the Option key.
4. Choose the USB drive as the startup disk.
5. Click the arrow button.
6. Follow the on-screen instructions to install macOS.

How do I boot into macOS from a USB drive?

1. Connect the bootable USB drive to your Mac.
2. Restart your Mac.
3. Hold down the Option key.
4. Choose the USB drive as the startup disk.
5. Click the arrow button.

What if my Mac doesn’t boot from the USB drive?

• Make sure that the USB drive is formatted as Mac OS Extended (Journaled).
• Make sure that the USB drive is inserted into a USB port on your Mac.
• Try restarting your Mac while holding down the Option key.
• If you are still having problems, try creating a new bootable USB drive.

How do I erase the bootable macOS USB drive?

1. Connect the bootable USB drive to your Mac.
2. Open Disk Utility.
3. Select the bootable USB drive in the sidebar.
4. Click the Erase button.
5. Choose Mac OS Extended (Journaled) as the format.
6. Click the Erase button again.

Can I use a bootable macOS USB drive to upgrade my Mac to a newer version of macOS?

Yes, you can. Simply boot into macOS from the USB drive and then follow the on-screen instructions to upgrade your Mac.

Can I use a bootable macOS USB drive to create a bootable macOS DVD?

No, you cannot. However, you can create a bootable macOS DVD using the Disk Utility app on your Mac.