FreeNAS is a free open sourced NAS (Network-Attached Storage) server.

why? because you have too much data to sit on your pc. so move it all onto
a networked server and hide it in your closet.

http://www.freenas.org/

FreeNAS Supports: CIFS (samba), FTP, NFS, AFP, RSYNC, iSCSI protocols, S.M.A.R.T., local user authentication, Software RAID (0,1,5) with a Full WEB configuration interface.

FreeNAS takes less than 32MB once installed on Compact Flash, hard drive or USB key.
The minimal FreeBSD distribution, Web interface, PHP scripts and documentation are based on M0n0wall.

Minimum requirements only asks for a minimum of 96MB of RAM. So basically a very simple PC with a cdrom. you can even install this to a 128mb USB stick to free up your Hard disk bays. Yep free them up so you can dump your 1.5tb drives in. get a case and a motherboard that can handle 10 HDD and you can have 15 terabytes of storage. mmmmmm....