Patent ID: 8510736

Claim:
A computer system comprising: a server; and a client computer comprising a disk device and the client computer is connected to the server via a network, wherein: the server comprises a takeout management module configured to issue a permit to the client computer when a takeout request is received from the client computer, the permit permitting the client computer to store data from a storage server to the disk device, the takeout request requesting using of data acquired from the storage server connected to the network under a condition of being disconnected from the network, and the client computer comprises: a first virtual machine environment where a first operating system (OS) and a takeout management utility operate, the first OS comprising a front end driver and the takeout management utility operating under the first OS; a second virtual machine environment where a second OS operates, the second OS managing the first OS and comprising a back-end driver and a security protector; and a takeout request transmitter configured to transmit the takeout request generated by the takeout management utility operating under the first OS to the server, and wherein the security protector configured to create a virtual disk image file on the disk device, and to connect a virtual bus for communication between the front-end driver and the back-end driver to access the virtual disk image file and store data acquired from the storage server connected to the network to the virtual disk image file by using the virtual bus, when the permit is received from the server.