This invention provides a method for operational management in a management server of a computer system, the computer system comprising more than one server to be managed and an OS disk image adapted to operate on any one of the servers, the management server being used to manage association between the OS disk image and one of the servers to be managed. The operational management method includes acquiring I/O device recognition information that the OS disk image on a first server to be managed recognizes, then acquiring physical device configuration information that indicates an I/O device configuration of a second server to be managed, and determining, on the basis of the acquired I/O device recognition information and physical device configuration information, whether the OS disk image operates properly when loaded into the second server and executed.