High-density optical mass storage system using overwriting for database file systems
Makoto Takayanagi, Manabu Yamamoto, Kikuji Katoh, Takaya Tanabe, Hisanobu Dobashi · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1997
An optical mass storage system using high-density recording media has been developed for large file systems such as multimedia databases, video-on-demand servers, and file backup systems. Quadruple-density 130-mm diameter magneto- optical disks raise the maximum capacity of this system to 2 tera bytes. The use of high-density media reduces the cost of file storage and the installation area and cuts the data transfer time. Compatibility with current systems using optical disks makes it easy to introduce this new system in place of older systems. For high transfer rate, we developed two disk drives. One uses two laser beams on one positioner and a new verification technique in the recording cycle by the write beam. The other uses overwritable media to reduce the overhead in the write cycle. The system cost is reduced by using standard components and high-density media. And high reliability is achieved by using cross access to drives and medium-handling mechanisms. This system is suitable for storing archived files on-line because it has enough capacity and access speed, unlike conventional systems whose archived data is stored off-line on magnetic tapes.