Patent ID: 7433934
Filing Date: 2008-10-07
Classification: H04L

Abstract:
1. A network storage virtualization method for accessing to network storage storing file data from a client, wherein a directory server is provided to store file management information, said method, when a request to access a file is issued to the network storage from the client, comprising the steps of: receiving the request to access a file from the client by a first network storage; transferring the received request to access a file, along with a first Internet Protocol (IP) address of the client, a second IP address of the first network storage, and a transmitting and receiving port number for transmitting and receiving packets, to the directory server from the first network storage, wherein along with the request being transferred the first IP address identifies a source of the request and the second IP address identifies a destination of the request; selecting a second network storage as the network storage for processing the request to access a file by the directory server based on the file management information, the second network storage having a third IP address; transferring the request to access a file, along with the first IP address of the client, the second IP address of the first network storage and the transmitting and receiving port number, to the selected second network storage from the directory server; processing the request to access a file on the second network storage to obtain a result of the processing of the request; and transmitting, from the second network storage, the result of the processing of the request to access a file to the client, by using the second IP address of the first network storage as identifying a source of the result being transmitted in place of the third IP address of the second network storage, the first IP address of the client as identifying a destination of the result being transmitted and the transmitting and receiving port number, wherein the processing step comprises the steps of: upon processing the request to access a file, by the second network storage, sending an update request to the directory server to update a file attribution of the file being accessed, and updating the file attribution of the file being accessed, said updating including updating at least an access time of the file being accessed.