A method for update writing in an array of DASDs in a reduced number of DASD track cycles. The method involves distributing data and parity blocks for each parity group across the array in failure independent form and reserving unused space. During a first cycle, the old data and parity blocks are read....http://www.google.ca/patents/US5375128?utm_source=gb-gplus-sharePatent US5375128 - Fast updating of DASD arrays using selective shadow writing of parity and data blocks, tracks, or cylinders
