At one of my primary schools i have 2 servers, a Windows Server 2k3 server that is the main (and only) DC on the network, it is also the DHCP and DNS Server. The Second Server runs Fedora and is a FOG Machine. I want to setup the Fedora machine to be the backup DC. Just so that there is some kind of backup in place.

Ive found a couple of guide telling me how to join it to the domain, which i suppose is the first step, but not quite what i want it to do.