For upgrade from MySQL to MariaDB that are of the same minor version (e.g. from mysql-5.5.x to mariadb-5.5.x) we don't have to do upgrade data. However, before upgrading from MySQL to MariaDB, we recommend to backup important data for the case something gets wrong.
Testing Yum repository for Fedora 18
We've prepared a testing Yum repository with RPMs for Fedora 18, which correspond with packages that are being prepared for Fedora 19.
The repository is located in http://hhorak.fedorapeople.org/mariadb-testday/mariadb-testday.repo and to use it, just copy it to
rootshell> wget -o /etc/yum.repos.d/mariadb-testday.repo \ http://hhorak.fedorapeople.org/mariadb-testday/mariadb-testday.repo
Going back to backed-up data if something gets wrong
In case something gets wrong, you can get back to backed-up data.