I'm reading the FreeNAS userguide and came across the statement: Note that hardware RAID configured as JBOD may still detach disks that do not respond in time; and as such may require TLER/CCTL/ERC-enabled disks to prevent drive dropouts. I'm using a '3Ware 9550SX-8LP RAID Controller' and see quite a few stories of people successfully running raid5 on 7.2k consumer SATA drives without issue. Are detached disks only a theoretical problem, or should I expect this to be a common occurrence?