Data storage apparatus and method allocating sets of data

摘要

A data storage apparatus has a plurality of storage spaces p for storing sets of data. Each of the spaces has: available (unused) space x1 for storage; a number x2 of data sets already stored; a number x3 of channels available for transferring data to the space; and a number x4 of times the space is scheduled to be used for reading out sets of data therefrom. An allocation factor Qp=f(ai, xi) is calculated for each space where ai are weighting factors ranking xi in order of importance. A data set is allocated to the space having the "best " (e.g. lowest) value of Qp at the time the data is to be allocated. Once allocation factors determined, then data may be allocated according to usage indices representing the ability of a space to store the data at the time of allocation.