Patent ID: 7908377

Claim:
A computer system comprising: at least one shared storage device connected to a communication network and utilized based on iSCSI (internet Small Computer System Interface); a plurality of computers each connected to the shared storage device through the communication network; a load distribution control part that selects one of the computers as a requested computer to be requested about command processing to distribute the load in the computers; and an access request control part that judges an acceptance of an access request issued by the requested computer for the command processing and allows an access to the shared storage device by the requested computer only when the access request is accepted, wherein the access request control part judges the acceptance of a plurality of access requests respectively issued by different and a plurality of the requested computers to allow each of the requested computers to use the shared storage device by using iSCSI at the same time, wherein a plurality of first computers included in the computers are not provided with an iSCSI initiator to access the shared storage device directly while a plurality of second computers other than the first computers among the computers are provided with the iSCSI initiator, and further the first and second computers are provided with a network file system respectively to share a file system through the communication network, wherein when the requested computer is selected from the first computers by the load distribution control part the access request control part selects a substitute computer from the second computers to access the shared storage device on behalf of the first computer selected as the requested computer, and wherein the first computer selected as the requested computer uses the network file system to utilize data in the shared storage device mounted on the second computer selected as the substitute computer, and wherein the substitute computer can generate an NFS (Network File System) server while the requested computer can generate an NFS client.