This comes late because I just joined the forum, but with six disks you may want to create two RAID5 arrays or if you want even better protection (and greater capacity than your single RAID5), use RAID1 or RAID10 (if available), where you are just mirroring your first 3 disks to your second 3 disks. A number of RAID5 building software today will build RAID5 capabilities on a number of disks above 3 (including 6).