A Study On The Policy Of Resource Allocation In XEN Virtualized Environment

With the development of information technology and computer application, many kinds of network data centers have been setup for web service. The performance of computer systems continue to be improved and the network data centers are becoming ever larger and more heterogeneous. In this case, resources of some network data centers are becoming idle, which result in a waste of hardware resources. In addition, part of network data centers need to renew computer hardware. However the original application running on the old servers can't run on new hardware because of hardware compatibility problems. The maintenance of network data centers need great human resources. Virtualization technology implements efficient use of resources and centralized management. The advantages of virtualization in information technology provide good conditions for the development of virtualization.Computing virtualization is a breakthrough in information industry and information technology. Virtualization is in essence making the best use of hardware resources. Computing virtualization technology provides a more flexible and dynamic IT architecture. There are many different types of virtualization solutions at present, solving different system performance issues from different angles, making the content of virtualization technology more and more powerful, which reflects good prospects for virtualization technology.With the application running in the virtualized systems, the usage of hardware resources has become complex and diverse, and it is difficult to allocate and use hardware resource among multiple virtual machines effectively. Most of virtualized systems are lack of flexible and efficient dynamic adjustment mechanism to allocate physical resources among various of virtual machines. As a result, the usage of physical resources in different virtual machines becomes imbalance, some of the virtual machine's physical resources is idle, and others may require more physical resources.More effort is needed to solve the problem of allocation of physical resources. Detection and analysis of the use and changes of virtual machine resources in detail, can help to adjust and optimize the usage of physical resources. In addition, how to schedule the virtual machine resource allocation in the data service center according to the user's performance requirements is also an urgent problem. To solve the virtual machine resource allocation problems mentioned above, taking into account of the dynamic changed requirements of applications, only by continuous detection of the use of resources and comprehensive analysis of all state of virtual machines, can make appropriate allocation of resources and use shared underlying resources in the virtualized system effectively.This paper studies virtualization technology, and introduce the architecture and basic technology of XEN virtual machine system in detail. This paper proposes two methods for the allocation of physical resources according to the QOS requirements in virtualized system. The first resource allocation method proposes a control model based on resource utilization. The control model can meets the QOS requirements through changing the resource utilization. The second resource allocation method is based on gray prediction model. The allocation of physical resources for virtual machine is according to the prediction of user request rate and resource and performance mapping model. Finally, the experiment proved that both of the two methods can control allocation of the physical resources very well in virtualized system and the service performance of the test results is also close to the required quality of service.