A virtual tape system includes an actual tape device having a magnetic tape which stores data. The virtual tape system includes a virtual tape storage device which stores data stored in the actual tape device as a virtual tape volume, first computers to be connected to a host computer which instructs a storing of data in the actual tape device, and a reading of data from the actual tape device, control an interface with the host computer, second computers which control the virtual tape volume of the virtual tape storage device, third computers which control a writing of the data into the actual tape device, and a local disk controller which stores the data in one of storage devices mounted one in each of the first computers, each of the second computers, and each of the third computers.