File storage system and method for managing file storage system

A storage system configured to use a second storage system, the storage system comprising:

• a first storage system storing a data;
• a processor;
• state management information storing a state of the data;
• a state information management unit that manages the state management information;
• and
• a data virtualization unit that manages data stored in the first storage system and the second storage system,
• wherein the processor processes an operation request of the data based on an operation request of the data from an application,
• wherein the state information management unit performs a state management information update process of the data based on an operation content related to the operation request,
• wherein the data virtualization unit performs a management process of the data between the first storage system and the second storage system based on the state management information,
• wherein the state information management unit creates a log of the operation request in addition to update of the state management information,
• wherein the data virtualization unit performs the management process of the data based on the log of the operation request,
• wherein the storage system includes a user directory which the first storage system manages,
• wherein the state management information, which the state information management unit manages, is associated with the user directory, stores a data state of the first storage system for the data having a same identifier stored in the second storage system, and a different identifier that is different from the same identifier, and
• wherein the data virtualization unit performs the management process of the data that reflects an operation, based on the operation content, on the first storage system to the file having the same identifier of the second storage system based on the data state of the first storage system and the different identifier in the state management information.