1. A storage system comprising: a storage component for storing data of a file; and a gateway component receiving a first type access request from a computer in accordance with a first type protocol, sending a second type access request to the storage component in accordance with a second type protocol, and managing a relation between a file specified by a path name and a file name in accordance with the first type protocol and an ID assigned to a content of the file in accordance with the second type protocol, the path name indicating a directory including the file, the file name being a unique identifier to specify the file in the directory, and the ID being a unique identifier to specify the content of the file in the storage component, wherein current data of a first file is stored in the storage component as a first content specified by a first ID in accordance with the second type protocol, wherein the gateway component receives an update request from the computer in accordance with the first type protocol for the first file specified by a first path name and a first file name included in the update request, the update request instructing to update the first file by using update data, wherein the gateway component issues a write request, in accordance with the second type protocol, to the storage component to instruct the storage component to store a second content including the update data, and wherein a second ID different from the first ID is assigned to the second content in accordance with the second type protocol.