An information processing system includes I/O devices, I/O switches each of which is coupled to the I/O devices, multiple server apparatuses which are coupled to the I/O switch and with which a cluster can be constructed, and a management server. In the system, a management server is that: stores an identifier and a coupling port ID of the I/O switch to which any of the server apparatuses and any of the I/O devices are coupled; stores information as to whether or not each of the I/O devices can use loopback function for the heart beat signal; selects one of the I/O devices available for the loopback function in constructing the cluster between the server apparatuses; generates a heart beat path using the selected I/O device as a loopback point; and performs settings on the I/O device.

A server computer which determines the configuration of a file for configuring a plurality of virtual computers respectively is configured to comprise: an OS/AP file evaluation criteria table which stores evaluation criteria for judging whether to split and manage a file required for the configuration of the virtual computers; a user data evaluation criteria TBL; and a verification and splitting unit which judges whether the file conforms to the evaluation criteria, and determines a part of a file judged to conform to the evaluation criteria as a first file stored as an entity and determines the remaining part of the file as a second file for referencing an entity of a predetermined destination storage.

A storage device control method for operating a logical volume to which a control command cannot be issued directly from a host computer is provided. The host computer manages a storage device. The storage device includes a disk device which provides logical volumes and a disk control device which controls the disk device. The host computer issues a control command to a recognized volume in the disk control device. The disk control device operates a recognized volume which is an issue destination of the control command or an unrecognized volume contained in the control command. A logical volume to which the control command is to be issued from the host computer is determined by using definition information (a disk information table, a copy pair information table, or a copy group information table) concerning copy operation retained by storage control software which operates on the host computer.

In a wind turbine generator system including an AC exciting converter a grid side converter, and a controller configured to control the AC-exciting converter and the grid side converter, the controller operates a short-circuiting circuit when decrease in the grid voltage and increase in the DC voltage are detected.

Provided is a storage system capable of simply and promptly changing the operation of a storage subsystem as a stand-alone system and the operation of a storage subsystem as a virtual storage system. This storage system is able to set a first mode that operates as a stand-alone system and a second mode that operates as a virtual storage system from a management apparatus to each of the multiple storage subsystems.