METHOD FOR READING OBJECT FROM VOLUME HIERARCHICAL TYPE MEMORY SYSTEM AND INFORMATION PROCESSING SYSTEM

摘要

PURPOSE: To shorten the average time for which a user should wait so as to retrieve some object from an automatic optical disk library by a method which gives priority to a read request. CONSTITUTION: When a read request is received, it is added to a queue of held requests. All held requests relating to a volume currently mounted on an optical disk driving mechanism are processed first, and held requests relating the reverse side of the volume which is already mounted and held read requests relating to the unmounted volume having the largest number of held read requests are processed in order. The mean response time of the processed requests is determined and held requests relating to an unmounted volume having a response time that is larger than several times as long as the mean response time is increased in priority to evade the problem that a request is unprocessed for along time.