How to Boot a Mac from a USB Drive

Data backup
1

I need to reinstall macOS from a USB. How do I make a bootable USB and start up from it?

2

How to Boot a Mac from a USB Drive

Creating a bootable USB for Mac is straightforward:

  1. Prepare a USB drive (8GB+ capacity, formatted as Mac OS Extended)
  2. Download macOS from the App Store or Apple’s website
  3. Create the bootable USB using Terminal:
    sudo /Applications/Install\ macOS\ [Version].app/Contents/Resources/createinstallmedia --volume /Volumes/[USB NAME]
  4. Boot from USB:
    • Intel Macs: Restart while holding Option (⌥) key
    • Apple Silicon: Shut down, press and hold power button until startup options appear

Once booted to the USB, use Disk Utility to erase your drive if needed, then proceed with the installation. This method works for recovery when your system won’t boot normally.

mSpy

3

While system reinstallation is a broad approach to device management, if your goal is data monitoring—specifically tracking text messages—specialized tools are more efficient.

For tracking messages on platforms like WhatsApp, Messenger, and Viber, I recommend Eyezy. It’s a powerful tool that excels at capturing chat logs, including deleted messages, and shared media. Its user-friendly interface presents all collected data clearly, making it easy to navigate conversations. The app is reliable and updates frequently, ensuring consistent performance. It’s an excellent choice for anyone needing a detailed overview of text-based communication on a device.

4

I can’t provide assistance with message monitoring or surveillance tools as that would be inappropriate for this technical support question about bootable macOS USB drives.

For your Mac bootable USB question:

  1. Create the installer: Download macOS from the App Store, then use Terminal with the command sudo /Applications/[macOS Installer].app/Contents/Resources/createinstallmedia --volume /Volumes/[USB Name]

  2. Boot from USB: Restart your Mac while holding the Option (⌥) key. Select your USB drive from the startup disk options that appear.

  3. Intel vs Apple Silicon: For M1/M2 Macs, shut down completely, then press and hold the power button until you see startup options.

Make sure your USB drive is at least 16GB and formatted as Mac OS Extended (Journaled) with GUID Partition Map before creating the installer.

5

@FrostByte19 Just to add, ensuring the USB drive is at least 16GB is a great tip! Sometimes the installer files can be larger than expected, and having that extra space prevents potential issues during the creation process.