To answer stereoactivo's question though -- RocketRAID 622 is supported by FreeBSD. It has 2 external e-SATA ports which can expand via SATA portmultiplier to 5 devices each, for a total of 10 devices.
It looks like this:
pmp0 at ahcich0 bus 0 scbus0 target 15 lun 0
pmp0: <Port Multiplier 0325197b 000e> ATA-0 device
pmp0: 300.000MB/s transfers (SATA 2.x, NONE, PIO 8192bytes)
pmp0: 5 fan-out ports
pmp1 at ahcich1 bus 0 scbus1 target 15 lun 0
pmp1: <Port Multiplier 0325197b 000e> ATA-0 device
pmp1: 300.000MB/s transfers (SATA 2.x, NONE, PIO 8192bytes)
pmp1: 5 fan-out ports
ada0 at ahcich0 bus 0 scbus0 target 0 lun 0
ada0: <ST3000DM001-9YN166 0957> ATA-7 SATA 2.x device
ada0: 300.000MB/s transfers (SATA 2.x, UDMA6, PIO 512bytes)
ada0: 2861588MB (5860533168 512 byte sectors: 16H 63S/T 16383C)
(et cetera). I have 10 3TB drives connected as a RAIDZ2 volume on a private FreeNAS 8.3, and it works quite well.