According to IDC's Worldwide Quarterly Server Virtualization Tracker, the overwhelming majority of IT shops using virtualization in a production environment are working with VMWare products. They may be running Windows in their enterprise, but those Windows environments are running on the VMware platform in many cases. Hyper-V, Microsoft's entry into the market, is gaining ground, but several factors may keep IT admins loyal to VMware. It has a bigger head start in this space, has a very stable product with a history of reliability, and has a loyal following (if attendance at VMWorld last week is any indication).
[ Read J. Peter Bruzzese's first installment in this two-part series: "The hypervisor wars rage on: A look at the new Hyper-V R2." | To learn more about vSphere 4.0, see InfoWorld's "The once and future virtualization king." ]
I had a chance to interview David Davis, one of the leading technical trainers for Train Signal and a vExpert, which is an award similar to the Microsoft MVP. The vExpert title is given to individuals who have significantly contributed to the community of VMware users and helped spread the word about virtualization over the past year.
So to start with, what exactly is vSphere?
VMware vSphere is a suite of products. The vSphere suite replaced the previous version of the suite called Virtual Infrastructure. vSphere is sold in various levels, depending on what features of the suite you want. All levels of vSphere include VMware ESX or ESXi (commercial, not free) and you must buy some version of vCenter. Examples of some of the features in the vSphere suites are VMHA, SVMotion, and the new Fault Tolerance (FT), which lets you run twin VMs in tandem across two hardware nodes, but with only one visible to the network so that if the primary goes offline, the backup VM takes over with no application outage.
What is the difference between vSphere and ESX?
vSphere is the suite of products, while ESX is the hypervisor that you load on each server that will participate in the vSphere virtual infrastructure. ESX commercial is available in "full/classic" and ESXi versions. It's important, however, that readers not confuse ESX with ESXi Free Edition -- these are very different. ESX is a part of vSphere enterprise virtualization suite, whereas ESXi Free Edition is for small businesses that want to get started in virtualization.
What makes VMWare's vSphere a compelling product for a Microsoft admin if Hyper-V is free?
First, I should point out that VMware offers ESXi, and like Hyper-V stand-alone ESXi is free. ESXi has a number of features that Hyper-V does not, like memory overcommitment. Second, I truly love Microsoft and its products, but I also try to be open-minded enough to pick the "best of breed" product.
Now, back to vSphere. vSphere is compelling for Microsoft admins because it has so much more product maturity than what Hyper-V offers. That isn't some kind of smack in the face to Hyper-V. The truth is that VMware has been crafting vSphere for over 10 years now, so it is natural that it offers more maturity than the very young Hyper-V. What do I mean by maturity? Well, vSphere offers things that Hyper-V just doesn't. I mentioned memory overcommitment. To me, that is a show-stopping feature that a hypervisor must have. By being able to overcommit and balloon memory for my VM guests, I can get many more VMs on a single server. That is going to equate to higher consolidation ratios, fewer physical servers, less infrastructure, less power and cooling, less administration, and lower costs.
Where does Hyper-V fall short of vSphere?
I hate to stir the pot but since you asked! I mentioned memory overcommitment and ballooning of memory in the guest VMs. But what about features like SVMotion [Storage VMotion, which allows you to leave a VM in place but move the VM guests virtual disks from one ESX servers local datastore to a shared SAN datastore, or vice versa], fault tolerance, data recovery, and add-on applications? Both VMware's offering of add-on apps and that of third parties is huge. What apps does Microsoft offer to add on to Hyper-V? SCVMM? Anything else? And what third-party providers have apps to add on my Hyper-V? Not many. At VMworld, there were hundreds of third-party companies offering thousands of applications for vSphere. To me, it's this kind of community that makes vSphere such a powerful choice.
Will Server 2008 R2 close the gap slightly with Hyper-V v2 and live migration?
If the "gap" is the gap in features between vSphere and Hyper-V, I would say no. Hyper-V started 10 years behind VMware in development and features. It isn't going to make that up in a short period of time. As Microsoft keeps adding features, so does VMware. I just see Microsoft trying to copy existing features of VMware so that they can say they are closing that gap. Still, as Microsoft adds more, so does VMware, and thus, that "gap" is never really closed.
For those new to vSphere and Hyper-V, what are some good ways to learn about them?
Of course, there are a ton of great Web sites out there like InfoWorld. For me personally (and maybe I am a little biased because I am the author of Train Signal's vSphere video training course), I think that video training options are one of the best choices out there. With video training, you are going to pay maybe 10 percent of the price of a classroom course, you can learn at your own pace, and learn from wherever you are (on your iPod or laptop).
You were at VMworld 2009 this week. What did you learn there that is related to this ongoing VMware-versus-Microsoft virtualization battle?
VMworld 2009 was truly awesome! I met so many smart and friendly people who are tremendously passionate about virtualization!
Now concerning the ongoing Microsoft-versus-VMware virtualization battle, I think that a lot of noise is being generated by both companies and by supporters on each side. I think that both companies see the importance of virtualization as it is likely the single most important piece of software infrastructure in the datacenter. That is why you see Microsoft and VMware both trying to ratchet up the rhetoric to win market share.
What I advise server administrators is to try out these virtualization options. There is no replacement for seeing the differences with your own eyes. Try out the free VMware ESXi, try out Hyper-V stand-alone edition, and try out the 60-day evaluation of vSphere. Try performing some test physical-to-virtual conversions and get a real understanding of how the management of these differing virtualization options compares.
It will certainly be interesting to see how these two giants battle it out with features going forward. Competition can only be a good thing for the world of virtualization. It prevents complacency from the development side. Herbert Hoover said, "Competition is not only the basis of protection to the consumer, but is the incentive to progress."