1. A system, comprising: a controller; and a plurality of memory modules in communication with the controller over a bus; wherein the controller is configured to: manage the association of a global logical address space with a physical address space: wherein each memory module has a physical address range and the global logical address range is mapped to a physical address range; the global logical address range being greater or equal to the sum of the physical address ranges; and wherein when a memory module is replaced with a memory module having a larger physical address range, the additional physical address range is mapped to a previously unmapped range of the global logical address range.