The present invention relates to providing security functionality over computer system mass storage data, and more particularly relates to a system and method of transparent data backup on either local or remote storage devices such as SATA storage devices. According to aspects of the invention, the system is transparent to operating system and application software layers. That makes it unnecessary to make any software modifications to the file system, device drivers, operating system, or applications, or installing specialized applications or hardware. In embodiments, the snapshot functionality of the invention is implemented entirely in hardware, and is not designed to slow down performance of the rest of the system.