Comments - Migrating from MySQL 5.1.31-community >> MariaDB 5.5

To migrate from MySQL 5.1 to MariaDB 5.5, it should be enough to uninstall MySQL packages without removing the data, and install MariaDB packages (and make sure that mysql_upgrade was run after the new server was started). But it is always good to have a dump ready as well, and of course don't forget to make a backup before upgrading.

After you upgrade to 5.5, it might happen that the server won't start if you have some options in your config file that were deprecated earlier and removed in 5.5 (it could happen regardless whether you upgrade from/to MySQL or from/to MariaDB, only versions count here). One usual problem is default-character-set in the server config, although there might be more. In this case just read carefully what the error log says and act accordingly, or ask if you can't interpret it.

Regarding storage engines choice, for the best experience I would recommend to do it one step at a time. Upgrade, see if it runs all right for you and you don't have any problems. Then, you can check Aria vs MyISAM KB page and see if there are any differences that you find potentially useful for your data and workflow. Check all sections regarding advantages, disadvantages, differences to fix and differences not to be fixed.

Potentially you could also consider migrating to InnoDB, but this is definitely not something you should make a decision about lightly, it requires analysis and often the internal knowledge of applications you are using. Even more so for migrating to TokuDB.