Sub-block based storage device and management method thereof

Abstract

A sub-block-based storage device includes a memory device configured to include a plurality of memory blocks, a work memory storing instructions, and a memory controller communicatively coupled with the memory device and the work memory and configured to manage the plurality of memory blocks. Each block of the plurality of memory blocks includes a plurality of sub-blocks having different capacities. The memory controller is configured to execute the instructions to manage used sub-blocks which store valid data from among the plurality of sub-blocks, manage free sub-blocks which are empty from among the plurality of sub-blocks, select a garbage collection source block from the used sub-blocks, select candidate destination blocks by comparing a size of valid data stored in the garbage collection source block and each of sizes of the free sub-blocks, and select a garbage collection destination block from the candidate destination blocks.