VMware has been dominating the virtualization market since virtualization hit the data center. Other hypervisors
have been trying to change that, but to no avail. Until now. New features in Microsoft’s Hyper-V R2 SP1 look like it might change the virtualization landscape by giving Microsoft server shops a cheaper option with comparable capabilities.
Hyper-V 2008 R2 SP1’s new features
With the release of the latest Hyper-V version in Windows 2008 R2 SP1, some important new features have been added that make the hypervisor more attractive to shops that formerly would have only considered VMware. The most important facet is live migration. You can now move a virtual machine (VM) from one Hyper-V host to another host while keeping it live. The absence of this feature was an important reason some companies previously did not use Hyper-V.
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Another new feature in Hyper-V is Dynamic Memory. With this, VMs don’t use a fixed amount of memory, but instead use dynamic memory assignment. This allows more flexibility in the total amount of available memory on your server. Virtual Machine Snapshot allows administrators to take a snapshot before making important modifications on a virtual machine.
VMware sites not swayed by Hyper-V
Most enterprises have a virtualization solution, which encompasses much more than just a couple of hypervisor hosts. For those companies with a VMware-based infrastructure in place, Hyper-V is not likely to be attractive, as the Microsoft offering isn't as complete as the VMware offering.
Hyper-V most attractive to new virtualization customers
Another part of the market consists of new virtualization customers. For these, Hyper-V is an option they can use without much hassle. Hyper-V is included in Windows Server 2008 R2, so it’s already in place for customers using Windows in their network, which makes it easy for administrators to integrate Microsoft servers such as Exchange and MS SQL into the Hyper-V environment.
Even for environments that don't have many Windows servers in their network, Hyper-V is an interesting option to consider. The free version of Hyper-V contains advanced features such as live migration and high availability (HA). In contrast, companies that start with the free VMware version and later want to add functionality such as HA and live migration, can only do that by buying expensive additional licensing.
Hyper-V vs. VMware tests inconclusive
The latest version of Hyper-V and VMware’s product offer comparable features, but VMware is more sophisticated. VMware offers smarter memory management and that makes it more efficient in handling VMs that run different operating systems. For Windows-only environments, this argument isn't that important, as Hyper-V is tuned to run Windows servers in the best possible way.
VMware says vSphere performance is still superior (PDF). A performance test running 30 virtual machines on a VMware vSphere 5 machine and the 30 VMs on Microsoft Hyper-V R2 SP1 was conducted, and according to VMware, vSphere outperforms Hyper-V by 18.9%. But does that mean that VMware is the winner? Probably not.
If you search for reports about which virtualization solution is fastest, you'll find some that indicate that, given the test method they've used, VMware is faster; others indicate that Hyper-V is faster. And it might happen that if you compare them yourself, you'll have different findings. Comparing speed isn't really going to help you find the best solution for your customers, for whom the most important question is whether or not the solution best fits their environment.
If multiple operating systems are used on the hypervisor, customers can benefit from the better memory management models that VMware has developed to run these OSes in the most efficient way. For those that don't have any virtualization at all yet, and especially those that are using Windows servers on a large scale already, Hyper-V seems to be the more obvious choice. Even if a customer doesn't have a large Windows install base yet, Hyper-V offers a better starter package, and that means that customers get more value for their money.
About the author:
Sander van Vugt is an author and independent technical trainer, specializing in Linux since 1994. Van Vugt is also a technical consultant for high-availability (HA) clustering and performance optimization, as well as an expert on SLED 10 administration.