How To Create Bootable USB Drive Using dd Command

Creating a bootable USB drive is a crucial task for installing or repairing operating systems. While there are many GUI tools like Rufus or BalenaEtcher, Linux users have a powerful alternative: the dd command. It’s fast, reliable, and available by default on most Unix-based systems.

This guide walks you through the steps to create a bootable USB using the dd command from the terminal.

⚠️ Disclaimer

The dd command is very powerful and does not warn before overwriting data. Be extra cautious when specifying the destination drive, or you could lose important data.

Step-by-Step Guide

Step 1: Insert Your USB Drive

Plug in your USB drive. It should be at least 4GB for most modern ISO images.

Step 2: Identify Your USB Drive

Open a terminal and run:

lsblk

Look for your USB drive (usually /dev/sdb or /dev/sdc). Do not use partitions like /dev/sdb1 — you need the whole device.

Example output:

NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      8:0    0  120G  0 disk
├─sda1   8:1    0  100G  0 part /
└─sda2   8:2    0   20G  0 part [SWAP]
sdb      8:16   1   8G   0 disk

In this example, the USB is /dev/sdb.

Step 3: Unmount the USB Drive

If it’s automatically mounted, unmount it using:

sudo umount /dev/sdb*

Step 4: Write the ISO to USB Using dd

Now use the dd command. Replace input.iso with the path to your ISO file, and /dev/sdX with your USB drive (e.g., /dev/sdb).

sudo dd if=/path/to/input.iso of=/dev/sdX bs=4M status=progress oflag=sync

Explanation:

• if=: input file (your ISO)
• of=: output file (your USB device)
• bs=4M: read/write in 4MB chunks for faster speed
• status=progress: shows ongoing status
• oflag=sync: ensures data is written properly

Example:

sudo dd if=ubuntu-22.04.iso of=/dev/sdb bs=4M status=progress oflag=sync

Step 5: Wait for Completion

This process may take a few minutes. Wait until the terminal returns to prompt. Do not remove the USB during this process.

Step 6: Safely Eject the USB

Once done, flush any remaining cache:

sync

Now remove your USB safely.

Conclusion

Using the dd command to create a bootable USB is a reliable and quick method for Linux users. Just be sure you double-check the destination device to avoid overwriting valuable data. Whether you’re installing Ubuntu, Fedora, or Arch, this method works across all major distros.

Mark Vincent

Tech enthusiast and content creator passionate about making technology simple for everyone. I share practical tips, guides, and reviews on the latest in computers, software, and gadgets. Let’s explore the digital world together!