A memory device comprising: a buffer memory, BFM; and a memory controller configured to: obtain map data, MD, and meta data for recovering the map data from at least one external storage device (310_1-310_5); store the map data and the meta data obtained from the at least one external storage device in the buffer memory, the buffer memory being allocated for the at least one storage device (310_1-310_5); translate a logical address corresponding to the at least one external storage device into a physical address of the buffer memory; and send the map data and the meta data to the at least one external storage device in response to detecting a sudden power-off event, wherein the at least one external storage device comprises a plurality of storage devices (310_1-310_5), characterized in that the memory controller is configured to obtain information for determining priorities of the plurality of storage devices from the plurality of storage devices, for the purpose of storing the map data and the meta data, and determine the priorities based on the information, and wherein the information comprises any one or any combination of: information about a residual power of a power storage, PS, connected with a bus, SW_CXL, connecting a host, the plurality of storage devices (310_1-310_5), and the memory device to each other; information about a residual power of power storages respectively connected with the plurality of storage devices; information about a residual storage space of each of the plurality of storage devices; and information about an input/output bandwidth of each of the plurality of storage devices. a buffer memory, BFM; and a memory controller configured to: obtain map data, MD, and meta data for recovering the map data from at least one external storage device (310_1-310_5); store the map data and the meta data obtained from the at least one external storage device in the buffer memory, the buffer memory being allocated for the at least one storage device (310_1-310_5); translate a logical address corresponding to the at least one external storage device into a physical address of the buffer memory; and send the map data and the meta data to the at least one external storage device in response to detecting a sudden power-off event, wherein the at least one external storage device comprises a plurality of storage devices (310_1-310_5), characterized in that the memory controller is configured to obtain information for determining priorities of the plurality of storage devices from the plurality of storage devices, for the purpose of storing the map data and the meta data, and determine the priorities based on the information, and obtain map data, MD, and meta data for recovering the map data from at least one external storage device (310_1-310_5); store the map data and the meta data obtained from the at least one external storage device in the buffer memory, the buffer memory being allocated for the at least one storage device (310_1-310_5); translate a logical address corresponding to the at least one external storage device into a physical address of the buffer memory; and send the map data and the meta data to the at least one external storage device in response to detecting a sudden power-off event, wherein the at least one external storage device comprises a plurality of storage devices (310_1-310_5), characterized in that the memory controller is configured to obtain information for determining priorities of the plurality of storage devices from the plurality of storage devices, for the purpose of storing the map data and the meta data, and determine the priorities based on the information, and information about a residual power of a power storage, PS, connected with a bus, SW_CXL, connecting a host, the plurality of storage devices (310_1-310_5), and the memory device to each other; information about a residual power of power storages respectively connected with the plurality of storage devices; information about a residual storage space of each of the plurality of storage devices; and information about an input/output bandwidth of each of the plurality of storage devices.