Synchronize two Xserve

Hello, I got 2 Xserve. One is used for different services and the other is used for testing new softwares and new services. I would like to synchronize the first one on the second. I mean the data and evrything that can make the secons xserve reboot with the same state of the first one. Like a backup server. Thank you in advance if somebony can answer Excuse for my english