A method of operating a data storage device which includes a first memory device, a second memory device, and a memory device storing a translation map is provided. The method includes receiving either a first identifier (ID) or a second ID and a virtual address from a host, selecting one of a first physical address and a second physical address from the translation map using either the first ID or the second ID and the virtual address, and reading data from one of the first memory device and the second memory device using the selected physical address and transmitting the data to the host. The translation map includes information about mapping the first ID and the virtual address to the first physical address of the first memory device and information about mapping the second ID and the virtual address to the second physical address of the second memory device.