Patent ID: 9733986
Date: 2017-08-15
CPC Classifications: G06F,Y02D

Claim:
1. A computer system comprising: a plurality of servers in which virtual machines are arranged; a plurality of power supply apparatuses that supply electric power to the servers; and a control apparatus that controls arrangement of the virtual machines in the servers, wherein the control apparatus solves an integer programming problem whose objective function is total power consumption by the plurality of servers and by the plurality of power supply apparatuses, wherein the total power consumption is described as a function of the arrangement of the virtual machines; and the control apparatus arranges the virtual machines based on a solution of the integer programming problem, wherein for each of the plurality of servers, (a) power consumption due to virtual machines arranged in the server and (b) the greatest number of virtual machines executed by the server are set, wherein for each of the virtual machines, a unit size when the virtual machine operates is set, for each of the power supply apparatuses, power consumption is set according to (a) electric power continually consumed by the power supply apparatus and (b) electric power supplied to the servers by the power supply apparatus, the control apparatus formulates as the integer programming problem, an electric power saving problem of a data center that includes the servers, the power supply apparatuses, and the control apparatus by converting into a linear inequality, a logical expression concerning a variable indicating on or off of a server and a variable indicating the number of virtual machines arranged in the server, by using (a) a condition that the server is turned on if at least one virtual machine is arranged in the server and (b) a condition that the number of virtual machines arranged in the server does not exceed the greatest number of virtual machines, and the solution of the integer programming problem includes at least the number of virtual machines to be arranged in each of the servers.