Optimizing Random Retrievals from CLV format Optical Disks

One technique often employed to improve retrieval performance from storage devices is to red;cee seek costs by to clusterin quently accessed data toget er ‘ii R locations on the storage device that are ph sically close. For magnetic disks etermlning the best position B on the disk to place frequently accessed data is strai optical disks with htforwarcl, for t eir fi many different recording formats the solution is much more difficult. We develop a detailed model for the E lacement of data on Constant inear Velocity (CLV) format optical disks that includes distribution of stora e ca acity across the disks surface whit is variable for CLV “t R format optical disks), the seek erformance of the disk drive, de avs r dye ,to yotational latency, and t& &l;on of ac$esses ovet We derive closed form expressio;s which determine the position of frequently accessed data that will minimize the expected cost of random accesses to the data set.