A data storage device may include: a nonvolatile memory device comprising a plurality of memory blocks, each having a plurality of pages, wherein each of the pages is divided into a plurality of segments having predetermined segment offset values, and the plurality of segments are grouped into a plurality of segment groups, each comprising segments having the same segment offset value; and a controller suitable for storing data in a first segment group among the plurality of segment groups until the first segment group includes no more empty segments.