Method for accessing distributed file system

Abstract

In order to access a distributed file system (DFS) of the present invention using a conventional protocol such as the one for an NFS or a CIFS without making a modification on a client side, a gateway unit for receiving a conventional protocol and performing processing in conformity the protocol is provided for a DFS server. The gateway unit emulates a directory structure in a file system such as the NFS or CIFS. When the DFS is a write-once read-many file system, update processing is converted into processing for creating a new generation file, and reference processing is converted into access to a latest generation file in a generation-managed file group. The gateway unit then accesses a DFS file via a DFS processing unit.

1 . A distributed file system (DFS) comprising:
 a plurality of DFS servers coupled to a network, for distributing a file for storage; and   a gateway unit for converting a protocol for accessing a centralized file system into a protocol capable of accessing the distributed file to access the distributed file;   wherein at least one of the DFS servers is provided with the gateway unit.   
   
   
       2 . The distributed file system according to  claim 1 , wherein the gateway unit creates a request for the distributed file system from a request for the centralized file system, thereby accessing the distributed file system, and creates a result of the request for the centralized file system from a result of the request for the distributed file system, using the protocol for the centralized file system. 
   
   
       3 . The distributed file system according to  claim 1 , wherein the gateway unit receives the request for making access in the centralized file system having a directory structure and accesses the distributed file system not having the directory structure, a file in the centralized file system being identified by a location of a directory in which the file resides and a unique file name in the directory, while the file in the distributed file system being identified by an identifier uniquely assigned in the distributed file system irrespective of a location of the file.