Patent ID: 7590667

Claim:
A file replication method for creating, in a distributed file system including a plurality of network storage apparatus and a replication system each connected to a network, the replication system having a management table for managing attribute information of all files and all directories in a first network storage apparatus as a replication source, a partial copy of data stored in the first network storage apparatus into a second network storage apparatus as a replication destination, said method comprising the steps of: preliminarily recording replication information indicating whether or not each of the files and the directories stored in said first network storage apparatus is an object to be copied in said replication system; preliminarily examining whether or not each of files and directories, that is indicated as an object to be copied, in said first network storage apparatus and each of copied files and directories maintain consistency, and setting a synchronization flag to each of files and directories which is proved to be consistent with a copy thereof; receiving a file access request from a client; judging that a replicating operation should be performed with execution of said file access request under conditions that said file access request is an updating file access request and that an access target of said file access request is a file or a directory which is indicated as an object to be copied and to which the synchronization flag is set; simultaneously transferring, if a result of said judgment is such that the replicating operation should be performed, said updating file access request to said first network storage apparatus and to said second network storage apparatus; collecting from said first network storage apparatus and from said second network storage apparatus responses to the updating file access request and making the collected responses into one response indicating that the updating file access request is done; and sending said one response to the client.