US Patent 11392310 Memory system and controller

A memory system includes a memory device including a plurality of memory blocks, and a controller for controlling the memory device. The controller stores user data in an original block selected among the memory blocks. When the original block becomes a closed block, the controller generates a copy block by copying each page of the original block into a page having the same page address of a free block among the memory blocks, and stores map data associated with the user data in the memory device, the map data including a logical address of the user data, an address of the original block, an address of the copy block, and a common page address. The common page address is a page address which is in common in the original block and the copy block. In embodiments, the controller limits the number of copy blocks according to a configurable copy level.