Real-Time Staging in Optical Disk Library

摘要

A new real-time staging technique in which disks are rated according to the likelihood of use, even with respect to storage location, is explained. In this technique, the exchange algorithm for the disks in a storehouse is simplified by disk management in groups; i.e., disks are exchanged between groups according to likelihood of use. Here, if a storehouse in an optical disk library is divided into N groups, real-time staging can reduce the total travel length of a robotic hand to as little as 1/ N of the conventional method. Moreover, if the prefetch and postrestore processes are also used to speed up the disk exchange operation at the disk drive, the total travel length is similarly shortened to 2/3 N of the conventional method, and the total travel time to 1/3.