A Tutorial on RAID Storage Systems

RAID storage systems have been in use since the early 1990's. Recently, however, as the demand for huge amounts of on-line storage has increased, RAID has once again come into focus. This report reviews the history of RAID, as well as where and how RAID systems fit in the storage hierarchy of an Enterprize Computing System (EIS). We describe the known RAID configurations and the advantages and disadvantages of each. Since the focus of our research is on the performance of RAID systems we devote a section to the various factors which affect RAID performance. Modelling RAID systems for their performance analysis is the topic of the next section and we report on the issues as well as briefly describe one simulator, RAIDframe, which has been developed. We conclude with section which describes the current open research questions in the area

Large-Scale Structure in the Universe

Cosmologists are currently researching the theory of large-scale structures, which are in essence groups of neighbouring galaxies. Recent “galaxy-hunts” have resulted in data for hundreds of thousands of galaxies being made publicly available, and it has become infeasible to isolate large-scale structures by hand from this data. Furthermore, it is difficult for cosmologists to visualise such structures by simply observing the galaxies that comprise the structure; they need a graphically rendered system in which they can change their viewpoint and observe the structure from any position desired. We present a system that identifies large-scale structures from datasets of galaxy information, and then displays the data using OpenGL in such a way that the user can “fly” through space in realtime, observing not only a single structure but the entire dataset and how structures are positioned relative to each other