From Fedora Project Wiki
PreUpgrade is an application users run on an existing Fedora 8 or above installation, that resolves and downloads packages required to upgrade Fedora. While PreUpgrade downloads the necessary packages, users are free to continue using their systems. This gives you a experience similar to a live upgrade.
To use PreUpgrade to upgrade to a newer Fedora release:
- Back up all important data before upgrading as a general best practise.
- Run the
yum update
command as root to make sure all packages are updated to their latest versions.
- Preupgrade is installed by default in recent versions. Run the
yum install preupgrade
command as root to install PreUpgrade otherwise.
- Run the
preupgrade
command as root to start the PreUpgrade application. If you prefer a command line application, runpreupgrade-cli
instead.
- Select the Fedora release you want to upgrade to on the Choose desired release screen, and click the Apply button.
- When all of the packages have downloaded, reboot your system to start the Fedora installer and upgrade to the next release.
For further information, refer to the PreUpgrade feature page.