"Based on embedded Linux, the TS-509 stores the OS and NAS
applications in flash ROM, which Qnap says improves "stability."
The device supports Linux, Unix, Mac OS X, and all major Windows
desktops. RAID support includes RAID 0 (disk striping), RAID 1
(mirroring), RAID 5, RAID 5+ (hot spare), RAID 6, and JBOD (linear
disk volume), says Qnap."