Earlier Peter at Percona posted an interesting article about MySQL upgrades. As a database consultant, it’s not uncommon for me to have enterprise-level customers that still run MySQL 4.0 or 4.1 - for a number of reasons that I will enumerate later, this kind of migration can be tricky. I just finished such a major upgrade so I will share my opinion on the subject.
If you are in a replicated environment you may want to migrate one of your slaves first as a prototype. Dumping and reloading is the recommended way because of many storage file format changes between 4.0 and 5.0 versions. For heavy databases I usually choose the parallel dump approach to save some precious time, either maatkit’s mk-parallel-dump or domas mituzas’ mydumper tools will do the trick.
Note that binary …[Read more]