Patent ID: 8397232

Claim:
A virtual machine system, comprising: a virtual machine monitor that executes on a physical machine for running a plurality of virtual machines, the virtual machine monitor including: a virtual battery manager for managing a virtual battery for running a virtual machine, the virtual battery holding electric energy used by the virtual machine, the virtual battery being capable of discharging and being charged; a schedule manager for allocating a resource of the physical machine to the virtual machine; a resource quota manager for managing resource allocated time for each of the plurality of virtual machines in accordance with status data acquired from the schedule manager, the status data indicating an allocated status of the resource on each of the plurality of virtual machines; a discharge calculator for calculating a discharged amount of the virtual battery by calculating energy consumption of the virtual machine with reference to a consumption policy and a consumption allocation table, in response to a discharge condition of only when a total amount of the resource allocated time for the virtual machine during a predefined time period is greater than a predefined threshold value, the consumption policy defining a maximum amount of total energy shared by the plurality of virtual machines, the consumption allocation table containing an allocated ratio of energy consumption for each of the plurality of virtual machines; and a discharger for decreasing a battery level of the virtual battery.