1. A method comprising: grouping a user data portion of a flash memory arrangement into a plurality of mapping units, wherein each of the mapping units comprises a user data memory portion and a metadata portion; forming the mapping units into a plurality of groups, wherein the groups are associated with at least one lower tier of a forward memory map; for each of the groups, determining a last written mapping unit within the group, wherein the last written mapping unit includes mapping data in the metadata portion that facilitates determining a physical address of other mapping units within the group; forming a top tier of the forward memory map that includes at least physical memory locations of the last written mapping units of each of the groups; and determining a physical address of a targeted memory using the top tier and the metadata of the at least one lower tier.