Abstract: In a computer system, there is provided the information representing empty areas generated when data sets are stored in a magnetic disk apparatus. From that information, the total capacity of empty areas and the deree of nonuniformity in size of empty areas are derived. If the result indicates that a sufficient effect is brought about by effecting recompilation processing of restoring the data sets by packing empty areas, the recompilation processing is carried out.

Abstract: A method of assinging software resources such as files and programs to memory devices is disclosed which uses first storage for storing therein the access frequency to a memory device for causing each type of service request to utilize each of software resources and second storage for storing therein the processing speed, allowable utilization and storage capacity of each of memory devices and in which the allocation of each of said software resources to the memory devices is determined on the basis of information stored in the first and second storages so that a total time taken to access the memory devices is minimized while being restricted by the allowable utilization and storage capacity of each memory device.