I have the above mailserver running on an embedded box for about 2 years now. All working perfectly as expected! I now have another machine exactly the same as the original. Same h/w, same SSD, same OS. Given it the same server hostname. Different LAN static address (obviously). I have installed the same Perfect server s/w as above. Have not configured in any way yet. What I want to do now is to rsync from the original machine to the new machine all the files necessary to effectively clone the configuration. And to repeat this at regular intervals (daily?) so that I can switch to the second machine if a fault occurs on the first. 1/ Which files and directories need to be rsync'ed? 2/ Do I need to stop or lock mysql while syncing the databases? Sorry if this has been asked before.