1. A memory system, comprising: a first sub-memory comprising at least one nonvolatile memory; a second sub-memory comprising at least one volatile memory; wherein in response to a memory reference failure that has occurred in a cache memory, a read reference failed data or a write reference failed data are loaded and stored to the second sub-memory from a storage, wherein the data stored to the second sub-memory is transferred and stored to the first sub-memory, and wherein in response to the memory reference failure that has occurred in the cache memory, the data of the first sub-memory transferred from second sub-memory is provided to the cache memory.