In a method of operating one or more nonvolatile memory devices including one or more memory blocks, each memory block includes a plurality of memory cells and a plurality of pages arranged in a vertical direction. Pages arranged in a first direction of a channel hole are set as first to N-th pages. A size of the channel hole increases in the first direction and decreases in the second direction. Pages arranged in a second direction of the channel hole are set as (N+1)-th to 2N-th pages. First to N-th page pairs are set such that a K-th page among the first to the N-th pages and an (N+K)-th page among the (N+1)-th to 2N-th pages form one page pair. Parity regions of two pages included in at least one page pair are shared by the two pages included in the at least one page pair.