XigmaNAS (formerly Nas4Free) is a great free solution for a NAS box, trouble is that without proper configuration it will not properly work with Active Directory consistently and can have issues with inheritance of permissions. These are the steps we take at RMTT to get them stable in an Active Directory environment. ///

Build hardware RAID Array (hardware RAID still faster than software RAID of XigmaNAS)

-- Hardware RAID might be marginally faster than software RAID, but completely negates all the benefits of using ZFS, including portability of drives to new server without needing a proprietary hardware controller...