Abstract: An expandable modular data storage array for storing and backing up data transmitted from a host computer including a plurality of data storage devices, a plurality of substantially identical, vertically stacked storage device housings adapted to slidably receive a data storage device, and mechanical connection elements for releasably connecting the top of one storage device housing to the bottom of a storage device housing stacked thereon. The array is connectable to a host computer and receives data and corresponding parity data therefrom. The parity data are indicative of data intended to be stored, from which parity data the intended data are reconstructable.