How to Create a Bootable Linux USB Drive on macOS and Windows (Step-by-Step Guide)

How to Flash a USB Drive with Linux on macOS and Windows (Step-by-Step Guide)

Linux is one of the most powerful and flexible operating systems in the world. If you’ve ever wanted to try it out or install it on your computer, one of the first steps is to create a bootable USB drive from a Linux ISO file.

A bootable USB allows you to:

• Try Linux without installing it (“Live” mode)

• Install Linux on your computer

• Troubleshoot and repair existing operating systems

In this detailed guide, we’ll cover everything you need to know to flash a USB drive with Linux — for both macOS and Windows — along with explanations for each step, and tips for avoiding common mistakes.

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    What You’ll Need

Before we start, make sure you have the following:

1. A USB Drive

   • Capacity: At least 8GB is recommended.

   • Warning: Flashing will erase all data on the USB drive, so back up anything important first.

2. A Linux ISO File

   • This is the operating system image you’ll write to your USB.

   • Download from the official site of your preferred distribution:

     • Ubuntu

     • Linux Mint

     • Fedora

     • Debian

3. A Flashing Tool

   • macOS: balenaEtcher (easy) or Terminal (advanced).

   • Windows: Rufus (recommended) or balenaEtcher.

4. A Computer with Administrator Access

   • You’ll need permissions to install software and write to drives.

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    Part 1 — Flashing Linux on macOS

Option 1: Using balenaEtcher (Easiest)

If you’re new to Linux or just want the simplest method, use balenaEtcher.

Steps:

1. Download balenaEtcher from etcher.balena.io and install it like any other Mac application.

2. Launch balenaEtcher — you’ll see three main options:

   • Flash from file (choose your Linux ISO)

   • Select target (choose your USB drive)

   • Flash! (start the process)

3. Click "Flash from file" and browse to your downloaded Linux ISO file.

4. Click "Select target" and choose your USB drive from the list. Make sure it’s the right one.

5. Click "Flash!" and wait. This may take several minutes depending on your USB speed.

6. Once complete, macOS may display a message saying “The disk you inserted was not readable.”

   • This is normal — macOS can’t read Linux partitions.

   • Just click “Ignore” and eject the drive.

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Option 2: Using macOS Terminal (Advanced)

This method is faster but riskier. You’ll be using the dd command, which will overwrite the target drive without confirmation.

Steps:

1. Insert your USB drive and open Terminal (Applications → Utilities → Terminal).

2. Type:

   bash
   diskutil list
   

   Identify your USB drive (e.g., /dev/disk2).
   Important: Double-check the size to avoid erasing your main drive.

3. Unmount the USB drive:

   bash
   diskutil unmountDisk /dev/disk2
   

4. Write the ISO to the USB:

   bash
   sudo dd if=/path/to/linux.iso of=/dev/rdisk2 bs=1m
   

   • Replace /path/to/linux.iso with the full path to your ISO.

   • Use rdisk instead of disk for faster writes.

5. Wait until the process finishes. You won’t see progress unless you press CTRL+T to display a status update.

6. Eject the drive:

   bash
   diskutil eject /dev/disk2
   

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    Part 2 — Flashing Linux on Windows

Option 1: Using Rufus (Recommended)

Rufus is one of the fastest and most reliable tools for creating bootable USBs on Windows.

Steps:

1. Download Rufus from rufus.ie (you can use the portable version — no installation needed).

2. Insert your USB drive into the computer.

3. Open Rufus. Under Device, select your USB drive.

4. Click SELECT and choose your Linux ISO file.

5. Under Partition scheme:

   • MBR for older BIOS-based systems.

   • GPT for newer UEFI-based systems.

   • If unsure, check your system’s boot mode in BIOS/UEFI settings.

6. Leave other settings at their defaults unless you have special requirements.

7. Click START. If prompted, choose “Write in ISO Image mode”.

8. Wait until the progress bar reaches 100%. This may take a few minutes.

9. Safely eject your USB drive.

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Option 2: Using balenaEtcher

The process is identical to the macOS steps:

1. Download balenaEtcher.

2. Select your ISO file, USB drive, and click Flash!.

3. Wait for it to finish and eject the drive.

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     Part 3 — Booting from Your Linux USB

Now that your USB is ready:

1. Insert it into the target computer.

2. Restart the computer.

3. Enter the boot menu:

   • Windows PCs: Usually F12, F10, or Esc.

   • Macs: Hold Option (⌥) at startup.

4. Select your USB drive from the list.

5. Choose “Try Linux” (Live mode) or “Install Linux”.

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    Troubleshooting Tips

• USB Not Detected in Boot Menu?

  • Check if your BIOS is set to boot from USB.

  • On older systems, enable Legacy Boot mode.

• Boot Error Messages?

  • Try a different USB port (preferably USB 2.0 for older systems).

  • Re-flash the USB — sometimes the first write fails.

• Slow Performance in Live Mode?

  • This is normal; running an OS from USB is slower than from an internal drive.

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    Final Notes

Flashing a Linux USB drive is the first step into the Linux world. Whether you’re testing it out or planning to install it permanently, you now know how to prepare a bootable USB on both macOS and Windows.

Take your time, double-check your USB drive before writing, and you’ll avoid most beginner mistakes.