FreeNAS

Freenas is an GPL program that can be downloaded from http://www.freenas.org. FreeNAS is a free NAS (Network-Attached Storage) server, supporting: 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 40MB once installed on Compact Flash, hard drive or USB key. The minimal FreeBSD distribution, Web interface, PHP scripts and documentation are based on M0n0wall.
 * The FreeNAS wiki can be found Here