1. A management server that manages a virtual network, including plural types of virtual resources generated by plural types of virtualization technologies, constructed on an information processing system coupled with devices including a server device, a storage device and a network device by a network, comprising: a managing table unit for holding a creation pattern for specifying either the plural types of virtual resources created by the plural types of virtualization technologies and a connection pattern for specifying either connection relations between the plural types of virtual resources; an information extracting unit for extracting information of a plurality of virtual resources and information of a plurality of connections between virtual resources, from setting information set in the devices in accordance with the creation pattern and the connection pattern; and a topology information generating unit for generating logical topology information of the virtual network in accordance with the extracted information.