A memory system includes a nonvolatile memory device having a plurality of physical sectors, a mapping table, and a memory controller including a plurality of hash functions. The memory controller is configured to access the physical sectors using the mapping table and the hash functions. The memory controller is configured to receive a sequence of logical block addresses (LBAs) from a host and logical sector data for each of the LBAs, generate a first virtual address by operating a selected hash function among the hash functions on a first logical block address (LBA) among the sequence, compress the logical sector data to generate compressed data, and store the compressed data in a first physical sector among the physical sectors that is associated with the first virtual address.