System including a plurality of data storage devices connected via network and data storage device used therefor

摘要

Embodiments of the present invention help improve the process for updating parities accompanied by the writing process. According to one embodiment, a host controller transmits a write command and new data to a hard disk drive (HDD). The HDD reads old data at a region where the new data are to be written. The HDD then XORs the new data and the old data to generate a pseudo-parity. The HDD sets the pseudo-parity in a data frame addressed to both of a horizontal parity disk drive HDD and a diagonal parity disk drive HDD and transmits it. The horizontal parity disk drive HDD and the diagonal parity disk drive HDD update the parities using the pseudo-parity.