By using an effective virtual machine placement algorithm

computing resources can be allocated optimally

therefore the utilization efficiency of cloud computing resources can be also improved. Based on analyzing the problems in resource allocation

a virtual machine placement algorithm is proposed by using complementary mechanisms. Firstly

based on the resource complementarity relationship among virtual machines

the virtual machines with smaller resource granularity are combined into a new virtual machine. Then

based on the resource complementarity relationship between the virtual machine and the server

the virtual machine is placed in the complementary server in turn

so that each resource type in the server is distributed evenly. Simulation results show that the number of servers and the energy consumption in the data center are decreased effectively

and the usage efficiency of cloud computing resources has been improved by using the CBVMP algorithm.