How to Boot Ubuntu from an External Hard Drive: A Comprehensive Guide

Booting Ubuntu from an external hard drive is a handy technique for those who want to temporarily use Ubuntu for specific tasks or projects without installing it on their main computer. This method involves several steps, including preparing the external hard drive, installing Ubuntu, and configuring the computer's BIOS or UEFI settings. Below is a step-by-step guide to help you through the process.

Step 1: Prepare the External Hard Drive

Backup Data

Ensure that you have backed up any important data on the external hard drive as the installation process will likely erase existing data. This step is crucial to prevent the loss of any personal files or work.

Download Ubuntu

Visit the official Ubuntu website and download the ISO file for the version you want. Make sure to select the appropriate version, such as the LTS (Long-Term Support) version for stability and long-term updates.

Create a Bootable USB Drive

You will need to create a bootable USB drive from the ISO file. You can use tools like:

Rufus (Windows) Etcher (Windows, macOS, Linux) UNetbootin (Windows, macOS, Linux)

Follow the tools' instructions to create the bootable USB drive. This step is essential for the installation process.

Step 2: Install Ubuntu on the External Hard Drive

Connect the External Hard Drive

Plug the external hard drive into your computer. This drive will serve as the installation medium for Ubuntu.

Boot from the USB Drive

To boot from the USB drive:

Restart your computer and enter the BIOS/UEFI settings. This usually involves pressing a key like F2, F10, DEL, or ESC during startup. Change the boot order to prioritize the USB drive. Typically, you can do this by navigating to the 'Boot' or 'Boot Order' option in the BIOS/UEFI settings.

Start the Installation

Select the Installation Type. During the Ubuntu installation, choose the type of installation that suits your needs. For external booting, choose Something else for customizing the partition layout. Create the necessary partitions: Root Partition (/): At least 20 GB formatted as ext4. Swap Partition: Optional but recommended if you have limited RAM. The size can be equal to your RAM size or double. Home Partition (/home): Optional for user files. Install the Bootloader: Make sure to install the bootloader GRUB on the external hard drive (e.g., /dev/sdb) and not on your internal drive. Finish Installation: Follow the prompts to complete the installation process. It is recommended to restart the computer and remove the USB drive after the installation is complete.

Step 3: Boot from the External Hard Drive

To boot into Ubuntu:

Restart Your Computer: After the installation, remove the USB drive and restart your computer. Enter BIOS/UEFI Again: If necessary, go back into the BIOS/UEFI settings to ensure the external hard drive is set as the primary boot device. Boot into Ubuntu: Save the settings and exit. Your computer should now boot from the external hard drive and you should see the GRUB menu allowing you to select Ubuntu.

Additional Tips

Boot Menu: Some computers allow you to select the boot device temporarily by pressing a specific key like F12 during startup. Check your computer's documentation for this option. Secure Boot: If you have Secure Boot enabled, you might need to disable it in BIOS/UEFI settings to boot Ubuntu. Check your system's documentation for instructions on how to do this. Performance: Running Ubuntu from an external hard drive may be slower than from an internal SSD, depending on the connection type. USB 3.0 is highly recommended for better performance.

By following these steps, you should be able to successfully boot Ubuntu from your external hard drive. If you encounter issues, check that the external drive is properly connected and that the BIOS settings are correct. Always ensure your data is backed up before proceeding with the installation and configuration steps.