In this tutorial I will show you how to install GlusterFS in a scalable way to create a storage cluster, starting with 2 servers on Centos 5.2. Files will be replicated and splitted accross all servers which is some sort of RAID 10 (raid 1 with < 4 servers). With 4 servers that have each 100GB hard drive, total storage will be 200GB and if one server fails, the data will still be intact and files on the failed server will be replicated on another working server.

Round Robin DNS is the simplest way to load balance a webserver between 2 or more servers in different location or to have network redundancy. For load balancing, it does not take in consideration the load on the servers but it's extremely easy to setup. It's also quite effective for network redundancy, you can plug a single server on 2 different network/switch and if one fail, all trafic will go on the available network.