[CentOS] Warm standby server with rsync

I'm trying to mirror a live server onto a slave server of identical hardware. Theory being that when the master server blows up I can change the IP of the slave, restore the db's, restart a few processes and make everyone happy again.

What is the best way of doing this? Can you literally rsync / (with the exception of perhaps /proc and /tmp) and create an identical copy of the master? Is there a better way to achieve this?

I've looked at using cluster suite but I don't think the instant(ish) and automatic failover justifies the cost of the shared storage.

TIA,

-- Nick B