Abstract: A failure independent, fault tolerant Direct Access Storage Device (DASD) storage subsystem comprising a Disk Control Unit and a number of Physical Devices is provided with a parity Generator for generating a parity for system records as the system records are transferred between the storage subsystem and a CPU of a data processing system. The parity is stored on a different unit so that if one unit containing portions of a system record becomes unavailable, the unavailable portion of the record is reconstructed during transfer to the CPU from the remainder of the record and the parity. The storage system of the invention can accommodate variable length data records without requiring operating system modifications.