Rumble Server

So I've just started running the rumble on the server that I have available to me. It has an Intel Xeon X3740 which really cranks out the results. I've seen some discussion on running multiple instances of the rumble, one for each core, and was wondering if there was anything special you had to do. I know you have to copy the directory for each instance but is that it? I'm going to run just one instance for the time being until I get some feedback out how to do this.

I'm also getting a lot of could not load robot errors. Is this because I am running Java 7?