Howtoforge posted a guide about installing a Web, Email and MySQL Database Cluster (Mirror) on Debian 5.0 with ISPConfig 3

This tutorial describes the installation of a clustered Web, Email, Database and DNS server to be used for redundancy, high availability and load balancing on Debian 5 with the ISPConfig 3 control panel. GlusterFS will be used to mirror the data between the servers and ISPConfig for mirroring the configuration files. I will use a setup of two servers here for demonstration purposes but the setup can scale to a higher number of servers with only minor modifications in the GlusterFS configuration files.

  Installing A Web, Email And MySQL Database Cluster (Mirror) On Debian 5.0 With ISPConfig 3