Performance of balanced disk array schemes

The balanced information dispersal algorithm (BIDA) provides attractive reliability enhancements as well as modest performance gains for the storage of data at a number of storage sites. A balanced disk array (BDA) is an application of BIDA. Although a BDA appears as a single, very reliable, fast direct-access device, it actually consists of a number of independent disks that store data according to a selected dispersal scheme. BDA devices offer exceptionally high fault tolerance combined with better performance than their constituent disks. As a result, a BDA achieves high quality with relatively low-quality components. BDA schemes also offer the flexibility to arrange for a desired ratio between read and write times. The authors discuss the construction, failure tolerance, and performance of BDAs.<>