[ Thanks to Falko
Timme for this link. ]
“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 6 with the ISPConfig 3
control panel. MySQL Master/Master replication will be used to
replicate the MySQL client databases between the servers and Unison
will be used to Sync the /var/www (websites) and /var/vmail (email
account data) folders.“1 Setting Up The Two Base Systems
“In this setup there will be one master server (which runs the
ISPConfig control panel interface) and one slave server which
mirrors the web (apache), email (postfix and dovecot) and database
(MySQL) services of the master server.”