Abstract :
Over the years, storage has become an increasingly valuable commodity as demand has increased. Businesses are expanding their storage capacity by 30 to 50 percent annually due to increasing volumes of customer, supply chain, and other important information; greater use of video and audio; and government data-storage mandates. To meet this demand, hard-drive storage density and capacity have grown by about 30 to 40 percent per year. In the process, the cost has dropped. Moreover, users want more performance from their disk drives, particularly those used in servers, to keep up with improvements in other parts of their systems. To respond to these challenges, drive manufacturers are turning to new techniques. Today, most are transitioning to perpendicular storage techniques, which provide modestly improved capacity with relatively slight changes to current production processes
