A Java Based Model for I O Scheduling in Tertiary Storage Subsystems

Modern I O subsystems include large storage servers which are con gured to include multiple on line and o line storage media and to deal with a large number of requests with unpredictable access patterns The problem of minimizing the cost of accessing data stored in all media is critical for the performance of the system Given the large storage requirements of modern applications Tertiary Storage Subsystems have become a crucial component of modern large scale storage servers This paper s contribution refers to the performance improvement of Tertiary Storage Systems by the use of speci c scheduling algorithms implemented under Java programming environment The emphasis of the paper is to present a general model to be applied to di erent Tertiary storage topologies under various computer platforms Magnetic tapes and tape libraries models are exam ined by the Java based simulation model in order to increase functionality and interactivity The Java based model is validated and experimented by three most widely used scheduling algorithms SORT SLF and SCAN policies Comparative analysis of the scheduling policies and discussion about the most bene cial scheduling policy on each model is provided