The I/O Virtualization Technology Research Based On Virtual Multi-channel Method

In the era of cloud computing and big data,virtualization is gaining great popularity in more and more application fields.Virtualization technology has also made considerable progress and development in recent years.Virtualized applications can be divided into two categories: the server virtualization and desktop virtualization.Some physical hardware virtualization,such as: CPU,memory,network adapter,and disk,which are involved in the server virtualization;and GPU virtualization is included in the desktop virtualization.Disk virtualization,network virtualization and GPU virtualization all belong to the I/O virtualization.As an important component of virtual machine systems,virtual I/O has non-negligible effects on the performance of virtual machine systems.Many techniques,such as CPU and memory in virtual machine have been well researched,and significant progress has been made in such fields.However,I/O virtualization is still a challenge in virtual systems.Based on Xen,this paper studies the I/O virtualization in virtual machine system,including virtual multi-channel disk I/O bandwidth allocation and its fairness,and multi-channel GPU virtualization method.The main research contents are as follows:1)This paper presents a Virtual Multi-Channel of Disk I/O(VMCD)method,and designs credit allocation mechanism,global monitoring strategy,and virtual multi-channel fair scheduling algorithm to increase disk I/O performance.Since multiple guest virtual machines(Dom Us)are running on a single physical device,disk I/O sharing and aggregated throughput utilization are still challenges in virtualized environments.Although several methods have been developed for disk I/O performance virtualization among multiple Dom Us,most of them suffer from one or more of the following drawbacks.(1)A fair scheduling mechanism is missing when requests converge together from multiple queues.(2)Existing met hods rely on better performance of the underlying storage system such as Solid State Drive(SSD).(3)Throughput and latency are not considered s imultaneously.VMCD is built on top of an ordinary storage utility,which prevents the interference among multi ple Dom Us by using separated virtual channel(V-Channel)and an I/O request queue for each Dom U.The proposed techniques are implemented on the Xen virtual disk and evaluated on Linux guest operating systems.Experiments results show that VMCD increases fairness by 70% approximately compared with the scheduler in Xen(CFQ,Deadline and Anticipatory schedulers).2)Based on Xen,we propose a novel architecture of multi-channel GPU virtualization(VMCG),design virtual multi-channel GPU scheduling algorithm accordingly.GPU virtualization as another kind of I/O virtualization technology,its development currently is far behind virtualization of other I/O,which is one of the bottlenecks in desktop virtualization.The existing GPU virtualization solutions are unable to meet these requirements at the same time,better performance,the strong sharing capability and full GPU function.VMCG running native graphics driver in Dom U,which leads to that Dom U can directly access performance-critical resources.And for other I/O which can't directly access the GPU,we provide a fully functional virtual GPU(v GPU)in Dom0.Multiple Dom Us can better share a single GPU fairly by the virtual multi-channel GPU scheduling algorithm.The experimental results show that VMCG increases the performance of GPU render by about 10%,and resource allocation fairness have improved significantly.