In the file storage system, each portion belonging to a data file is identified by its file ID and an offset along the data file, where the offset is a constant for the file and every file data portion is always kept at the same position within a memory page to be read or programmed in parallel. In this way, every time a page containing a file portion is read and copy to another page, the data in it is always page-aligned, and each bit within the file portion can always be manipulated by the same sense amplifier and same set data latches within the same memory column. In a preferred implementation, the page alignment is such that (offset within a page)=(data offset within a file) MOD (page size). Any gaps that may exist in page can be padded with any existing page-aligned valid data.