A method of controlling a first memory controller that controls a non-volatile memory device includes: the first memory controller receiving first data and a first physical address from a second memory controller via a first interface of the first memory controller; the first memory controller storing the first data in a non-volatile memory buffer of the first memory controller; and the first memory controller programming the first data stored in the non-volatile memory buffer in a first physical region of the non-volatile memory device corresponding to the first physical address.