Technological impact of magnetic hard disk drives on storage systems

Magnetic hard disk drives have undergone vast technological improvements since their introduction as storage devices over 45 years ago, and these improvements have had a marked influence on how disk drives are applied and what they can do. Areal density increases have exceeded the traditional semiconductor development trajectory and have yielded higher-capacity, higherperformance, and smaller-form-factor disk drives, enabling desktop and mobile computers to store multi-gigabytes of data easily. Server systems containing large numbers of drives have achieved unparalleled reliability, performance, and storage capacity. All of these characteristics have been achieved at rapidly declining disk costs. This paper relates advances in disk drives to corresponding trends in storage systems and projects where these trends may lead in the future.