How to mirror from one server to another?

[web_hoster]

Hello,

I basically want to have mirror sites set up on a different network in case the main one fails. What is the best way to do this? I would like to try it out with one of our servers that has roughly 140 domains on it. When the server goes down, it automatically kicks it to the other, backup server where the backups of sites are . Do I just use DNS and set up 2 different nameservers/IPs?

Thank you for your help.

[red9]

can't see how this could work unless there some sort of forwarding you could use on the server that goes down because when a customer logs into their control panel with their domain provider they have to enter a nameserver. Surely this nameserver will resolve to your servers IP address. To change server they would need to change this in the control panel.

Im sure someone will be able to provide a better answer soon though