Patent ID: 7685310

Claim:
A computer system having a plurality of host computers and at least one storage system that has a plurality of ports for connection to the plurality of host computers and provides volumes for the plurality of host computers via a storage network, wherein a host computer and a storage system are connected to each other through a single port, the storage system comprising: a port load monitoring unit for monitoring the difference in load between the plurality of ports; a path load monitoring unit for monitoring the load applied to a connection path between the plurality of host computers and the storage system; an identification unit for identifying, when the difference in load between the plurality of ports reaches or exceeds a predetermined value, the host computers connected to the port with the highest load in the plurality of ports; a connection control unit for disconnecting at least one of the identified host computers from the storage system; and a transmission unit for transmitting, when the host computer that has been disconnected from the storage system sends a reconnection request, a command for redirection to the port with the lowest load in the plurality of ports, to the host computer that has sent the reconnection request, wherein the identification unit calculates the average load between the port with the highest load and the port with the lowest load in the plurality of ports, calculates the load difference between the average load and the load in the port with the highest load or the port with the lowest load, and selects, from among the plurality of host computers, the host computer that applies the load closest to that load difference to the port, and wherein the storage system calculates the difference in load between the plurality of ports when the identified host computer has been redirected to the port with the lowest load, and if the difference in load between the plurality of ports when the identified host computer has been redirected to the port with the lowest load reaches or exceeds a predetermined value, the storage system executes the processing for identifying the host computers connected to the port with the highest load.