Is it just me or is a single RAID 5 array, with a hot spare, not a good way to go. That's been our setup, and we've never even needed the RAID to rebuild. It simply copies to the hot swap, which becomes part of the array, no extra overhead required on the disks, and we can come in to a beeping drive in the morning which we can have replaced next day. Seems like a no brainer to me. I haven't much looked into RAID 6 but 5 with a hot spare is working well.