Marc - the original poster isdoing exactly that. Commenting on those options. Do read the whole thread. Also I have posted in the past about mysql cluster at least.
Make sure you also review PostgreSQL PITR, which I've also discussed here in connection to a very nice set of scripts that give you a Magic Power over your moodle install.
Such is the power of Potent Magic, GIT and Pg. Search and ye shall find.
Hardware and performance
High availability - MySQL cluster v's replication
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