1. A system in communication with data storage, for storing data, and comprising: a first log structured array storing data in a storage device; a second log structured array in the storage device storing metadata for the data in the first log structured array, wherein the second log structured array is nested within the first log structured array, and wherein the first and second log structured arrays comprise separate instances of log structured arrays; a metadata area in the storage device shared by the first and second log structured arrays, including a second log structured array metadata area; and a component for allocating part of the second log structured array metadata area for metadata for an address space used by the first log structured array when the first log structured array needs to use the address space.