Patent ID: 6526420
Filing Date: 2003-02-25
Classification: G06F,Y10S

Abstract:
A method of constraint optimization in a storage system having a plurality of workload units and a plurality of storage devices, said method comprising the steps of:determining at least one objective function governing a non-linear performance model and a solver algorithm having a non-linear heuristic function; selecting at least one workload unit from said plurality of workload units; determining standards of said at least one workload unit; selecting at least one storage device from said plurality of storage devices; determining characteristics of said at least one storage device; generating an assignment plan for said at least one workload unit to said at least one storage device based on said at least one objective function; and evaluating said assignment plan against said at least one objective function; wherein said step of generating an assignment plan comprises assigning said at least one workload unit to said at least one storage device when said non-linear heuristic function is maximized, wherein said nonlinear heuristic function comprises at least one of a cosine-gradient function, a normalized-cosine-gradient function, a Toyoda adaptation gradient function, and a composite gradient function; and wherein said step of generating an assignment plan further comprises:calculating a set of first gradient functions for said plurality of workload units and said plurality of storage devices; determining which of said set of first gradient functions has the greatest value; assigning, based on said determining step, a workload unit of said plurality of workload units to a storage device of said plurality of storage devices; recalculating a set of new gradient functions for remaining workload units of said plurality of workload units and remaining storage devices of said plurality of storage devices; redetermining which of said set of new gradient functions has a greatest value; reassigning, based on said redetermining step, another workload unit of said plurality of workload units to another storage device of said plurality of storage devices; and repeating said recalculating, redetermining, and reassigning steps.