See How to Fully Install Ubuntu on USB, if you would rather run Ubuntu from an external USB drive using a method that works exactly like it would running from an internal drive. The following method creates a Live Ubuntu USB that utilizes a compressed Squashfs file system. As such, it continues to share many of the same upstream roots. It was originally based upon and derived from Debian. Ubuntu is a very popular Open Source Linux distribution created by Canonical Ltd. Ubuntu's Casper Persistent feature can also be used for saving and restoring changes on subsequent boots. In the following segment I show you how to use the Official Startup Disk Creator, made by the Ubuntu team to put Ubuntu on a USB Flash Drive. How to easily Create an Ubuntu Bootable USB with persistence from a running Live CD.
