中文摘要：

随着计算机软、硬件技术的不断进步和应用需求的日益增长，以计算机为中心的计算系统的应用范围越采越广，其复杂程度也在迅速提高，人们对如何评估和提高计算系统的可信赖性的需求日益迫切．首先给出了计算系统的可信赖性的定义，并系统地定义了一整套量化评价指标；同时，对计算系统面临的各种可信赖性威胁进行了详细的归类分析．传统的方法难以应对复杂系统面，临的各种可信赖性问题，人们仍在不断地寻求新的技术．虚拟化技术在这种应用背景下走向复兴，成为一大研究热点．介绍了已有的虚拟化技术在增强系统可信赖性上相关的研究成果，并且总结了虚拟化技术在增强系统可信赖性方面的各种特性和机制．然而由于现有的计算系统体系结构的限制，难以将虚拟化技术在增强系统可信赖性方面的优势充分地发挥出来．面向服务的体系结构（service oriented architecture，简称SOA）以其松散耦合、平台无关性等特点很好地适应了虚拟化技术的需求．因此，最后将SOA和虚拟化技术相结合，提出了一种增强计算系统可信赖性的系统架构，即面向服务的虚拟化SOY（service oriented virtualization），并且分析了SOV系统如何在遭受各种可信赖性威胁时，运用体系结构优势和虚拟化技术的各种机制保证系统可信赖性．

英文摘要：

With the advance of computer hardware and software techniques and the continuous growth of application requirements, the computing systems, which have computers as their centers, have increasingly broadened the scope of application, while the complexity is also growing quickly. The demand for evaluating and improving the dependability of computing systems is more and more urgent. This paper gives the definition of computing systems＇ dependability, and a series of quantitative indicators are presented to evaluate the dependability. At the same time, the threats to system dependability are classified and analyzed in details. Since the traditional methods are incapable of dealing with the diverse dependability problem faced by the increasingly complex systems, people are constantly searching for new techniques. In this context, the virtualization technique comes to its renaissance, and is rapidly becoming a major research focus in recent years. In this paper, the existing research results on applying virtualization to enhance the dependability of computing systems are summed up, and the main characteristics and mechanisms of virtualization on enhancing dependability are introduced. But due to the restrictions of the existing computing systems architecture, the superiority of virtualization can not work fully. Service Oriented Architecture （SOA） meets the requirements of virtualization well for the loosely coupled, platform independence characteristics. Therefore, at the last part of this paper, a framework which integrates SOA and virtualization is proposed to enhance the dependability of computing systems, which is called Service Oriented Virtualization （SOV）. This paper analyzes how this system framework can enhance the system dependability by mechanisms of virtualization and architecture superiority, when faced with many kinds of dependability threats.