A method for mirroring a memory in a memory system is provided to improve efficiency of a channel by installing a data section for storing data and a mirroring data section for copying the mirroring data to each memory device. The data is stored to the memory device and the data is mirrored to a predetermined area of the memory device(S10). A memory controller reads the data stored in the memory device and determines an error(S20). If the data includes the error, the data mirrored to the memory device is read from the memory device(S30). The memory device supports a mirroring mode for mirroring the data. The mirroring mode uses an MRS(Mode Register Set) and the memory device is a DRAM. The memory system uses an FBDIMM(Fully Buffered Double In-Line Memory Module).
