1. A memory system comprising: a non-volatile memory configured to store management information; a volatile memory configured to store at least one part of the management information; a controller configured to: load the management information stored in the non-volatile memory into the volatile memory at first timing; save the management information loaded in the volatile memory into the non-volatile memory at second timing; perform data transmission through the volatile memory between a host apparatus and the non-volatile memory; and update the management information stored in the volatile memory while performing the data transmission based on the management information; and a compression/decompression processor configured to compress the management information in the case where a first condition is satisfied and to decompress the compressed management information in the case where a second condition is satisfied, wherein the controller is configured to store the compressed management information in the non-volatile memory.