[stardotstar]

I run a cron hourly which dumps the databases to a db_latest.sql which overwrites the previous hour and therefore is a reasonably stable disk usage.
Then in the wee hours I do a time stamped daily dump with cron, compress the set of latest hourly's and dailys with bzip then rsync them off to another server.
I also have a weekly web tree/ft tree and home tree compression that rsyncs out over a staggered period of time.

The crons for the processes are also staggered and set to background and not interfere with the boards (especially important for the hourly) I have not perfected this from a performance point of view but my server is dedicated hardware so I have that luxury I guess.

I have felt the panic of not having a backup and finding myself up to the armpits in the guts of my db fixing something that shouldn't have gone wrong but did!
Now I backup as described and always do nontrivial mods on a dev board first.