Setup a SQL cluster of a few machines and have the rendundancy act as your first line of defense and have it structured something like this
Server 1: Apache, Mysql
Server 2: Mysql
Server 3: Mysql, somebackup to another media or offsite
This gives you a machine that can be dedicated to the main job, one for backingup and another that has just the db stuff just in case.
I am sure there is a brighter solution, but not being a DBA I am a little slow on this kind of stuff, plus not adminning in a few years, I am sure the tech got better since my foray into IT.