Cyclic Allocation of Two-Dimensional Data

Various proposals have been made for declustering two-dimensionally tiled data on multiple I/O devices. Recently it has been shown that strictly optimal solutions only exist under very restrictive conditions on the tiling of the two-dimensional space or for very few I/O devices. In this paper we explore allocation methods where no strictly optimal solution exists. We propose a general class of allocation methods, referred to as cyclic allocation methods, and show that many existing methods are instances of this class. As a result , various seemingly ad hoc and unrelated methods are presented in a single framework. Furthermore, the framework is used to develop new allocation methods that give better performance than any previous method and that approach the best feasible performance.