Research On Optical Disc Library Sorting

Survey shows that about 80% of huge amounts of data are infrequently accessed,called cold data. Because of its advantages, CD library is excellent to store them. For many applications, CD library as an online server shared by multiple users receives multi-user data streams in parallel and burn them into blank discs in real-time. Large amounts of data discs generated afterwards belong to different users chaotically, mixed in a series of temporary disc trays. In order to facilitate long-term management and retrieval,re-classified storage is necessary.CD classification problem can be solved by way of sorting. According to the characteristics of disc classification migration issues, it is proposed that times of migrating discs should be reduced first. After analysis of CD library running process, disc classification migration algorithms and strategies are proposed. Depending on the size of free disc slots space, three different classification and migration scenarios are presented each with time and space overhead. Realization is of detailed analysis and discussion.Three simulation test modules using MATLAB are: user data flow module, disc burning buffer module, disc sorting module. Test results imply that in order to reduce the overall migration time, high capacity discs and algorithms with least possible migrations are recommended. In three cases of spare disc slots, three best algorithms are presented.Simulation results show that the proposed disc classification migration algorithms can meet the functional requirements of the actual system to achieve the desired results. In three cases, the least number of migrations for 1000 randomly scrambling discs are: 2000 times, 2997 times, 2997 times.