1. For a re-programmable non-volatile memory system having a plurality of blocks of memory cells that are individually erased prior to data being written therein and that operates with an inventory of a minimum number of erased blocks ready to have data stored therein, a method of operation, comprising: receiving data of files logically addressed by unique file identifiers and offsets within the files, wherein said unique file identifiers and offsets within the files are used by the memory system for logically addressing the files, storing the received data of a first file as pages within one or more of the erased blocks that only partially fill a first one of the erased blocks, thereby leaving erased data storage capacity within the first partially filled block, and storing the received data of a second file as pages within one or more of the erased blocks that only partially fill a second one of the erased blocks, thereby leaving erased data storage capacity within the second partially filled block, and postponing consolidating valid data from the partially filled first and second blocks into another one of the erased blocks until at least the inventory of the number of erased blocks is deemed insufficient to maintain the minimum number.