The IBM 3850 mass storage system: Design aspects

The IBM 3850 mass storage system is a new concept in large data base storage. This paper explores the principal design objectives and the options chosen in designing the hardware and the data flow for the system. The 3850 is an approach that provides up to 472 × 10⁹bytes of storage, gives reasonable on-line storage cost comparable to manually loaded flexible media products such as half-inch tape drives, provides internally controlled data staging at the request of the host processor, and provides a parallel-path data flow. The parallel-path data flow in turn provides multiple staging and destaging-plus increased availability of data--by using full multiple data paths for all data.