Reliability Design for Large Scale Storage Systems

Data reliability are drawn much concern in large-scale storage systems built from thousands of storage devices, which highly depends on many inter-dependent system parameters, such as the replica placement policies, number of stored objects and so on. Previous work has discussed the impacts of these system parameters on reliability roughly and separately, and seldom provided their optimal values, nor mentioned their optimal combination. In this paper, we present a new object-based-repairing analytic model. Based on analyzing this model in three popular replica placement policies, we figure out the individual optimal values of these parameters at the beginning, and then work out their optimal combination. Compared with the existing models, our model is easier to solve while reaching more integrative and practical conclusions. These conclusions can directly and effectively instruct the designers to build more reliable storage systems.