After losing access to my server during a prolonged DDOS attack on my providers network, I am looking for a way to make my ISPConfig based hosting service more robust. I'm thinking about having a second server with a different provider at a different physical location and setting it up as a mirror of my current server. I know that there is an existing tutorial here for setting up a mirrored cluster but it says that it's a "proof of concept" so I'm not that keen on using it for a production service. Here are the questions... 1. Has anyone used this tutorial and found it to work OK? Is there a better way to create a redundant ISPConfig setup across 2 separate data centers? 2. If I do set up a mirror and run DNS on both, could I point the records on server 1 to the IP address of server 1 and the records on server 2 to the IP address of server 2? In my tiny brain I'm thinking that I can set up ns1.mydomain.com and ns2.mydomain.com so that if server 1 is down or unrechable, server 2 will start answering the DNS queries. I know there will be a caching lag but it's better than being offline for 3 days! 3. Will server 2 act as a secondary MX for email if server 1 is offline? I would also be interested to hear if anyone else runs a physically diverse setup and how you do it.