Operating System Virtualization: Practice and Experience

Proceedings of the 3rd Annual Haifa Experimental Systems Conference (SYSTOR 2010), Haifa, Israel, May 24-26, 2010


Operating system (OS) virtualization can provide a num- ber of important benefits, including transparent migration of applications, server consolidation, online OS maintenance, and enhanced system security. However, the construction of such a system presents a myriad of challenges, even for the most cautious developer, that if overlooked may result in a weak, incomplete virtualization. We present a detailed dis- cussion of key implementation issues in providing OS virtu- alization in a commodity OS, including system call interposi- tion, virtualization state management, and race conditions. We discuss our experiences in implementing such functional- ity across two major versions of Linux entirely in a loadable kernel module without any kernel modification. We present experimental results on both uniprocessor and multiproces- sor systems that demonstrate the ability of our approach to provide fine-grain virtualization with very low overhead.



Columbia University Department of Computer Science