While last week I showed how Ubuntu's performance has evolved as a KVM guest from Ubuntu 8.04 through Ubuntu 11.10, in today's article is a Linux virtualization showdown between VirtualBox, Xen, and KVM while using Ubuntu 11.10 on the Linux 3.0 kernel.
This Linux virtualization comparison is being done using a ZaReason notebook with an Intel Core i7 2630QM (Sandy Bridge) quad-core processor with Hyper Threading, 8GB of system memory, a 128GB Super Talent SSD, and NVIDIA GeForce GT 555M graphics. Ubuntu 11.10 x86_64 was used on the host with the Oneiric's Linux 3.0 kernel, Unity 4.22.0, X.Org Server 1.10.4, GCC 4.6.1, and an EXT4 file-system. Each VM instance had access to all eight logical cores and 6GB of system memory.
The VirtualBox 4.1.2, KVM, and Xen 4.1.1 components were all obtained from the Ubuntu Oneiric repository. Ubuntu 11.10 marks the return of Xen virtualization support for DomU guests now that the Xen support has been merged into the mainline kernel tree. The only Xen issue encountered when testing it with an Ubuntu 11.10 guest and host was the need for manually loading the xen-blkfront driver for disk support. While Xen is now available in Ubuntu, Canonical's continuing to support the Linux Kernel-based Virtual Machine (KVM) as their primary Linux virtualization technology. VMware's Linux virtualization support could not be tested in this article due to terms-of-use restrictions that prevent the benchmarks from being published.
Besides benchmarking VirtualBox, Xen, and KVM, the Sandy Bridge system was also benchmarked on bare metal for reference. The Xen support was tested in the HVM mode but not the para-virtualized configuration.