Abstract: In the environment of IaaS cloud,the key factor of the resource allocation management is how to place virtual machine.It is mostly probably that an improper placement strategy may cause the loss of resource and more energy consumption.Thus,a multi-objective optimization model was established which devotes to reduce the resource loss and energy consumption of the whole data center.Further more,a kind of placement strategy about virtual machine based on dynamic programming theory was proposed.In the strategy,the problem of placement is transformed into a knapsack problem of multi-stage decision,in which the knapsack problem is divided into a series of smaller sub-problems with the idea of dynamic programming.And the optimal solution of the original problem is obtained through solving the optimal solution of the sub-problems.Finally,the simulation experiment shows that this strategy can greatly reduce the energy consumption and the resource loss of data center.

Key words: Cloud environment,Resource loss,Energy consumption,Multi-objective optimization,Dynamic programming