A server control program for distributing a plurality of virtual servers to a plurality of physical servers, the server control program causing a computer to execute: predicting a second load of each of the virtual servers in future based on a first load of each of the plurality of virtual servers in a prescribed time period up to the present; selecting each physical server sequentially, from among the plurality of physical servers, and determining a schedule to distribute the plurality of virtual servers to the plurality of physical servers based on the second load of each of the virtual servers, the determining being performed by allocating the plurality of virtual servers to the physical servers, the determining including setting a number of physical servers to which the plurality of virtual servers are to be distributed to an initial value, wherein the initial value is calculated based on a total of the second loads of the plurality of virtual servers, and a product of the prescribed proportion and the total processing capacities of a physical server, for each of the plurality of physical servers, wherein the number of physical servers is increased to a value larger than the initial value under a certain condition, so that a total of the second loads of one or a plurality of the virtual servers distributed to each of the plurality of physical servers is within an acceptable range of a prescribed proportion with respect to processing capacity of said physical server, and wherein the acceptable range is between an upper limit that is greater than the prescribed proportion and a lower limit that is less than the prescribed proportion, and wherein the certain condition is that a given virtual server cannot be allocated to any of the set number of physical servers while maintaining the second loads allocated to the physical servers within the acceptable range; and issuing an instruction to distribute a portion or all of the plurality of virtual servers to a portion or all of the plurality of physical servers according to the schedule, wherein the step of issuing an instruction to distribute a portion or all of the plurality of virtual servers to a portion or all of the plurality of physical servers according to the schedule includes the step of issuing an instruction to turn off power to a physical server to which no virtual servers are allocated. predicting a second load of each of the virtual servers in future based on a first load of each of the plurality of virtual servers in a prescribed time period up to the present; selecting each physical server sequentially, from among the plurality of physical servers, and determining a schedule to distribute the plurality of virtual servers to the plurality of physical servers based on the second load of each of the virtual servers, the determining being performed by allocating the plurality of virtual servers to the physical servers, the determining including setting a number of physical servers to which the plurality of virtual servers are to be distributed to an initial value, wherein the initial value is calculated based on a total of the second loads of the plurality of virtual servers, and a product of the prescribed proportion and the total processing capacities of a physical server, for each of the plurality of physical servers, wherein the number of physical servers is increased to a value larger than the initial value under a certain condition, so that a total of the second loads of one or a plurality of the virtual servers distributed to each of the plurality of physical servers is within an acceptable range of a prescribed proportion with respect to processing capacity of said physical server, and wherein the acceptable range is between an upper limit that is greater than the prescribed proportion and a lower limit that is less than the prescribed proportion, and wherein the certain condition is that a given virtual server cannot be allocated to any of the set number of physical servers while maintaining the second loads allocated to the physical servers within the acceptable range; and wherein the initial value is calculated based on a total of the second loads of the plurality of virtual servers, and a product of the prescribed proportion and the total processing capacities of a physical server, for each of the plurality of physical servers, wherein the number of physical servers is increased to a value larger than the initial value under a certain condition, so that a total of the second loads of one or a plurality of the virtual servers distributed to each of the plurality of physical servers is within an acceptable range of a prescribed proportion with respect to processing capacity of said physical server, and wherein the acceptable range is between an upper limit that is greater than the prescribed proportion and a lower limit that is less than the prescribed proportion, and wherein the certain condition is that a given virtual server cannot be allocated to any of the set number of physical servers while maintaining the second loads allocated to the physical servers within the acceptable range; and issuing an instruction to distribute a portion or all of the plurality of virtual servers to a portion or all of the plurality of physical servers according to the schedule, wherein the step of issuing an instruction to distribute a portion or all of the plurality of virtual servers to a portion or all of the plurality of physical servers according to the schedule includes the step of issuing an instruction to turn off power to a physical server to which no virtual servers are allocated.