1. A method for partitioning storage of a data storage system comprising: selecting a plurality of storage groups associated with a plurality of allocation policies, each of said plurality of storage groups including one or more logical devices and being associated with one of the plurality of allocation policies, wherein said one allocation policy associated with said each storage group includes a first threshold specifying one of a minimum or a maximum amount of storage of a first of a plurality of storage tiers of physical storage devices used for storing data of the one or more logical devices of said each storage group associated with said one allocation policy and a second threshold specifying one of a minimum or a maximum amount of storage for a second of the plurality of storage tiers for storing data of the one or more logical devices of said each storage group, said second storage tier being different from the first storage tier, wherein said plurality of storage tiers have a relative performance ranking in which said first storage tier has a higher performance ranking than the second storage tier whereby physical devices of the first storage tier have higher performance characteristics than physical devices of the second storage tier; analyzing workload data for said plurality of storage groups; and partitioning storage of the plurality of storage tiers for use in storing data of logical devices included in said plurality of storage groups in accordance with criteria, said criteria including workloads of said plurality of storage groups, priorities of said plurality of storage groups, and said plurality of allocation policies associated with said plurality of storage groups, wherein each of said priorities represents a priority for a different one of the plurality of storage groups, wherein each of said workloads represents a workload for a different one of the plurality of storage groups determined using one or more metrics including any of I/O throughput and response time, a first of the plurality of storage groups has a first of said priorities and a first workload and a second of the plurality of storage groups has a second of said priorities denoting a lower priority than said first priority and said second storage group has a second workload that is substantially a same workload as the first workload, and wherein as a result of said partitioning, the first storage group has more of its data located in the first storage tier than the second storage group.