Patent ID: 8874952

Claim:
A computer system comprising at least one physical server, wherein the at least one physical server comprises: current-system physical devices; standby-system physical devices; and a virtualization mechanism which provides a plurality of virtual servers each comprising a current-system virtual device obtained by virtualizing the current-system physical devices, and a standby-system virtual device obtained by virtualizing the standby-system physical devices, wherein the virtualization mechanism is configured to: allocate, for occupied usage, the current-system physical devices to the current-system virtual devices of each of the plurality of virtual servers; and allocate, for shared usage, the standby-system physical devices to the standby-system virtual devices of the plurality of virtual servers, wherein, when a fault occurs in a first current-system physical device allocated to a first current-system virtual device of a first virtual server, the virtualization mechanism is configured to: configure a first standby-system physical device, which has not been configured as a physical device which is used at high priority by any of the standby-system virtual devices of the plurality of virtual servers, as a physical device which is used at a high priority by a first standby-system virtual device of the first virtual server; distribute a request issued from the first standby-system virtual device of the first virtual server to the first standby-system physical device configured as a physical device which is used at a high priority by the first standby-system virtual device of the first virtual server; and distribute a request issued from another standby-system virtual device of another virtual server to another standby-system physical device which has not been configured as a physical device which is used at a high priority by any of the standby-system virtual devices of the plurality of virtual servers when the another standby-system physical device exists.