In an apparatus and method for ensuring data in an external storage system, the system includes an external storage controller for transferring read data from at least one external storage device, such as a magnetic disk drive, to a host device and for transferring write data from the host device to...http://www.google.com/patents/US5588012?utm_source=gb-gplus-sharePatent US5588012 - Apparatus and method for ensuring data in external storage system
