Choosing the right foundation: which hypervisor do you evaluate?by Johan De Gelas on November 3, 2009 12:00 AM EST
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First of all, we were pretty excited to see so many comments and votes (5000!) on our last IT poll. It is good to see that professional IT is so much alive at Anandtech.com. So yes, we should have updated this blog quicker, to keep the momentum going. The reason why this update comes rather late is -once again - that we are working on the much delayed hypervisor comparison. Hundreds of tests have already been done, but we have added more tests to check important I/O performance factors such as VMDq and iSCSI performance.
And of course, the virtualization market is evolving fast. There is a new kid on the block: KVM. Two of the three most important Linux vendors, Red Hat and Canonical, have ripped Xen out of their distributions in favor of KVM. KVM has an interesting philosophy: it simply adds two kernel modules to the Linux kernel to turn the latter into a hypervisor. As a result, KVM can leverage the huge amount of Linux drivers and the Linux kernel improvements such as power management. Still, a virtualization solution needs to mature quite a bit before it is ready. And that is more than a cliche. Xen's support for Windows VMs was for example supposed to work at the beginning of 2007, as Xen introduced support for Hardware Virtual Machines at the end of 2006. But only around in the middle of 2008, we felt confident enough to say that Windows virtual machines work well on Xen. We reported:
"Xen 3.2.0 which can be found in the newest Novell SLES 10 SP2, is capable of running Windows 2003 R2 under heavy stress."
So it took Xen several major revisions to really get it right. It is unlikely that KVM will do this much quicker. We will be giving KVM some heavy stresstesting so we can tell you more than just hearsay.
In the mean time, a new survey by Centrify shows a still dominant VMware, but it also tell us that Hyper-V and Xen are making a lot of progress, growing strong enough to be dangerous opponents in the near future. I have been talking to tens of Small and Medium Enterprises (SME) in Belgium and the Netherlands. Our own tests show that VMware ESX is still the most robust hypervisor and most people concur. However VMware's half-hearted attempts to make vSphere more attractive to the SME does not create a lot of enthousiasm. If VMware does not create a more budgetfriendly solution for SMEs (and VMware, newsflash: most SME have more than 3 servers), we have the impression it may lose the server virtualization battle in the SME world, where everything is still possible. But those are my personal impressions. At the end of the day, what will happen in your working environment determines who will prevail. So let us know what you are planning...