Create and Use a Live Disk Edit on GitHub

What is a live disk?

Ubuntu is remarkably flexible. You can run a full version of Ubuntu from a USB drive (often known as a thumb drive, flash drive, or USB stick) or a DVD in what’s known as a live environment. Using a live environment (live disk) is useful for:

You can understand why a live disk is a handy tool to have around! Note that it’s typically called a live disk since you can use either a USB or DVD. USB is recommended, since it’s significantly faster.

How do I create a live disk?

The basic steps to create a live disk are as follows:

  1. Download an ISO copy of Ubuntu
  2. Connect a USB or DVD drive
  3. Use a special program (Startup Disk Creator, Rufus, unetbootin, or dd) to write the ISO to disk

If you’re upgrading or reinstalling Ubuntu, choose the version you plan on installing. If you’re using the live disk for recovery purposes, try and match the same version.

Ubuntu has provided step-by-step guides to create install media:

Create an Installation USB Create an Installation DVD
Using Ubuntu Using Ubuntu
Using Windows Using Windows
Using Mac OS X Using Mac OS X

Advanced: Using dd to create a live USB

If you have a Linux system available, you can create a live USB using a command line tool called dd. Please note, this is an advanced method. dd is a simple and powerful tool which can overwrite any drive, destination, or file. Use with caution!

Warnings aside, dd is safe and highly effective when used properly. Be sure to confirm your destination file of= before running the command. A screenshot is provided below the instructions for reference.

  1. Insert the USB drive
  2. Run lsblk or mount to get a listing of all block-level devices and their mountpoints
  3. Unmount the USB with umount /dev/[path-to-usb-drive]
  4. Write out your dd command. The following assumes the ISO is in the ~/Downloads folder and is being writing to /dev/sdf – substitute the correct paths for your system!
sudo dd if=~/Downloads/ubuntu-17.04-desktop-amd64.iso of=/dev/sdf

Confirm the output file path of= is correct – open a new terminal if needed!

  • If everything looks good, press Enter to write the ISO to disk.

Since dd is writing to a device at the block level, it requires elevated permissions via sudo. You will be prompted for your password.

The ISO is a large file, and it takes several minutes to write. The system might not look like it’s doing anything. Be patient! Once complete, dd will print a final count of blocks in/out.

If your dd completes immediately, it was likely written to a file instead of to your USB drive. Confirm the of= destination is correct (it should be a block-level device, like /dev/sdf) and try again.

Using dd

Booting from a live disk

After creating the live disk, insert the USB or DVD into your computer, then reboot or power on your system. You’ll need to tell the computer to boot from the live disk by holding a key right as you power on:

Laptops Desktops
Hold F7 or F1 Hold F12, F8, or F10

If done correctly, you should see a boot device selection menu, like one of the following images.

Boot menu

Use the arrow keys to select your USB or DVD drive, then press Enter to boot the selection.

You’ll be asked if you want to Install Ubuntu or Try Ubuntu without installing. Choose whichever is applicable:

Install Ubuntu Try Ubuntu
Reinstall Test hardware
Upgrade Try out Ubuntu
  Fix the bootloader
  Back up files
  Fix your environment

Ubuntu will boot into the installer or send you to the familiar Ubuntu dekstop. You can install Ubuntu from the live environment.

The live disk environment

Using the live environment

The list provided at the beginning of the article provides links to other articles on using the live environment for hardware testing, restoration/upgrades, and boot repair. The live environment has other purposes as well.

Recovering your normal environment

Since the live environment is a full Ubuntu installation, it works just like your normal environment. There are tools that allow you to chroot (change root) into your normal installation and work in your normal environment to repair a broken package or installation that is preventing you from booting normally.

Backing up files

Perhaps you’re reinstalling, or maybe you can’t boot but you want to try and recover and back up your files? The live environment will automatically detect and mount most file systems including Linux and Windows. You can then copy files from the disk to another external disk using the familiar Files utility.