Authors (if Research)
Paul Barham, Boris Dragovic, Keir Fraser, Steven Hand, Tim Harris, Alex Ho, Rolf Neugebauer, Ian Pratt, Andrew Warfield
Published at SOSP 2003
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 sacrice 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 efcient: 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.