Inside Xen 3.0: A XenSource White Paper

Virtualization has become a key requirement for the enterprise. This results from an urgent need to focus on reduced total cost of ownership (TCO) for enterprise computing infrastructure. In spite of – or indeed because of – the widespread adoption of relatively cheap, industry standard x86-based servers, enterprises have seen costs and complexity escalate rapidly. In addition to the capital expenditures to purchase them, each server in the data center costs an enterprise about an additional $10,000 per year to run, with costs including provisioning, maintenance, administration, power, real-estate, and hardware and software licenses.

At the same time, most servers today run at less than 15% utilization, meaning that most server capacity is wasted. Operating system (OS) virtualization, a concept pioneered by IBM in 1972 on the System 360, has become a key requirement to alleviate this problem because it enables increased utilization, allowing multiple operating system and application images to share each server, cutting both per-server capital cost and the overall lifetime operational costs. If every physical server can host multiple virtual servers, the overall required number of servers is reduced, and with that reduction come increased utilization, reduced complexity, and lower total cost of ownership.

Virtualization also offers many additional benefits – including development, staging and testing, dynamic provisioning, reduced patching, no-downtime maintenance, high availability and load balancing. Further, virtualization opens the door for enterprises to realize the promise of utility computing. But today’s virtualization offerings are crippled by poor performance, lack of security and scalability, and an inability to offer the fine-grained resource guarantees that are required to provide true application level SLAs and support high availability. To get high performance virtualization on today’s modern hardware takes a new kind of software: a low level, minimal, secure and high performance virtualization software layer called a hypervisor. The Xen open source hypervisor, created by the XenSource founders and now developed collaboratively by over 20 major enterprises working in the Xen project, is leading the industry in high performance enterprise virtualization. Moreover Xen is the industry’s first virtualization software to fully support Intel’s VT-x hardware virtualization support.