File access service system, switch apparatus, quota management method and program

A file access service system comprising:

• at least one terminal;
• a plurality of file systems;
• and
• an intermediate unit, inserted logically between said terminal and the plurality of said file systems,
• said intermediate unit including:
• means for providing a file access service in which said file systems are accessed as a virtual file system constituting a single file system as seen by said terminal;
• and
• control means for managing amount of use of storage resources of said virtual file system.

A switch apparatus connected for communication to at least one client and to a plurality of servers each having means for limiting amount of use of a storage resource of a respective file system;

• said switch apparatus receiving a file-access request from the client, assigning and transferring the file-access request to a suitable server utilizing prescribed layer information, receiving a response to the file-access request transmitted from the server, and transferring the response to the client that was the source of the file-access request;
• said switch apparatus including:
• a pseudo file system for managing directory trees of said file systems as a single consolidated directory tree obtained by combining the directory trees, and provides a file access service in which the file systems of said servers are accessed as a virtual file system constituting a single file system as seen by the client;
• and
• control means for managing amount of use of storage resources of said virtual file system.

A computer program product run on a computer constituting a switch apparatus connected for communication to at least one client and to a plurality of servers each having means for limiting amount of use of a storage resource of a respective file system;

• said switch apparatus receiving a file-access request from the client, assigning and transferring the file-access request to a suitable server utilizing prescribed layer information, receiving a response to the file-access request transmitted from the server, and transferring the response to the client that was the source of the file-access request;
• wherein said switch apparatus includes a pseudo file system for managing directory trees of said file systems as a single consolidated directory tree obtained by combining the directory trees, and provides a file access service in which the file systems of said servers are accessed freely as a virtual file system constituting a single file system as seen by the client;
• wherein said program causes the computer to execute the processes of:
• setting a set value with respect to each of said file systems that construct said virtual file system, wherein the set value limits amount of use of each storage resource of each of said file system;
• and
• controlling to vary at least one set value that limits amount of use of each storage resource of each of said file systems in accordance with amount of use of the storage resource in each of said file systems and the set value that limits amount of use of storage resources of said virtual file system.