This article will walk through the process of upgrading Fedora 21 to Fedora 22 with use of Fedora Updater tool called FedUp.
FedUp (FEDora UPgrader) is the official recommended tool for upgrading Fedora distributions (since Fedora 18) to latest versions. FedUp is capable of managing Fedora upgrades via a network repository or a DVD image as the upgrade package source.