Trends in It

Arvin R. Rosco Sir. Kim Ortega

3IT1 Feb. 12, 2016

Xen and the Art of Virtualization

Modern computers are suf_ciently powerful to use virtualization to present the illusion of many smaller virtual machines (VMs), each running a separate operating system instance. This has led to a resurgence of interest in VM technology. In this paper we present Xen, a high performance resource-managed virtual machine monitor

(VMM) which enables applications such as server consolidation co-located hosting facilities, distributed web services, secure computing platforms and application mobility.

Numerous systems have been designed which use virtualization to subdivide the ample resources of a modern computer. Some require specialized hardware, or cannot support commodity operating systems.

Some target 100% binary compatibility at the expense of performance.Others sacri_ce security or functionality for speed. Few offer resource isolation or performance guarantees; most provide only best-effort provisioning, risking denial of service.

This paper presents Xen, an x86 virtual machine monitor which allows multiple commodity operating systems to share conventional hardware in a safe and resource managed fashion, but without sacri_cing either performance or functionality. This is achieved by providing an idealized virtual machine abstraction to which operating systems such as Linux, BSD and Windows XP, can be ported with minimal effort.

Our design is targeted at hosting up to 100 virtual machine instances simultaneously on a modern server. The virtualization approach taken by Xen is extremely ef_cient: we allow operating systems such as Linux and Windows XP to be hosted simultaneously for a negligible performance overhead at most a few percent compared with the unvirtualized case. We considerably outperform competing commercial and freely available solutions in a range of microbenchmarks and system-wide tests.

Live Migration of Virtual Machines...