[CentOS] Copy OS live to different hardware

Hello,

I've got some CentOS 5.3 servers that I want to clone to a backup server, possibly a VM machine. I want this to be done while the server is up, and keep it synced at least once a day.

I've done this already by using RSYNC, but here's the twist: the backup machine could be different hardware, and needs to have a different IP address (so they don't conflict).

My question: exactly what files should I exclude, so that I copy everything -except- what pertains to the ethernet card(s), and hard drive mounts. I know of at least:

/etc/fstab /etc/sysconfig/network-scripts/* /var/run /proc

But what else? The original servers may have software raid, so those files can't be copied either.

Bob