Windows Virtualization With VMware or Hyper-V
Both VMware ESX or Microsoft's Hyper-V Have Their Own Advantages
© John Wu
Nov 8, 2009
Although it's a good idea to listen to technical engineers opinions when picking a Windows virtualization solution, getting a view of the big picture is also important to make the right decision for the organization. Both VMWare ESX and Microsoft Hyper-V (formerly known as Windows Server Virtualization) are hypervisor virtualization products.
Due to this, both are able to run multiple virtual machines and attain cost savings from buying less hardware. But the pricing of each virtualization solution varies significantly, especially for Windows shops with MS Volume Licensing.
If every IT organization had an infinite budget, nobody should choose anything other than VMware ESX, which is currently the superior virtualization product. However, most IT budgets today are stretched to the limit with the effects of the recession. IT executives need to consider other cheaper products, such as Hyper-V, that may not necessarily be best of breed but is still a good hypervisor vituralization solution.
OS Virtualization Support
VMware ESX supports many operating systems including many Linux distributions, most versions of Microsoft Windows from Windows 3.1 to Windows 7, Apple Mac OS X, Oracle Enterprise Linux, Novell Netware, and Sun Microsystem's Solaris.
Microsoft Hyper-V supports Novell's SuSE Linux 10 SP1 and SP2, which is a very competitive enterprise Linux solution, as well as the popular Red Hat Enterprise Linux (RHEL) 5.2, 5.3, and 5.4 in both x86 and x64 flavors. Fedora Linux, and Ubuntu are not supported, but some versions have been reported to work.
Although the long list of operating systems supported on VMWare is impressive, it's irrelevant for a Windows virtualization solution since everything runs on a supported Microsoft OS with Hyper-V. Even if there Linux systems in the shop, the most popular enterprise Linux solutions are supported with Hyper-V.
VMWare ESX's Technical Advantages
VMWare allows for memory to be over-committed, which means the memory allocated for all virtual machines exceeds the amount of RAM on the server. When a server needs a temporary increase in memory, VMWare is able to service it. Microsoft's Hyper-V cannot share memory between virtual machines.
VMWare vMotion allows for dynamic load balancing via virtualization. This means a virtual machine can move from one server to another without interruption. Microsoft has no equivalent dynamic load balancing solution in Hyper-V, but it uses Microsoft's Cluster Server (MSCS) from Windows 2008 for fault tolerance. Microsoft has a process called Quick Migration that moves a virtual machine from one server to another in the time needed to transfer memory over the network. During the migration, the virtual machine is suspended.
On the storage side, Microsoft recommends no more than one LUN per virtual machine. For VMware, there is no limit.
Cost Savings From Using Microsoft Hyper-V
The biggest drawback to VMware ESX is cost. It is more expensive and the licensing policies are less flexible and too complex. Some customers complain that the cost savings from virtualization are not visible to the point where the costs savings from hardware simply shifted to software.
Microsoft's Hyper-V is included in Windows 2008 Server. Microsoft also includes additional licensing breaks on guest operating systems for those who have Windows 2008 Server Datacenter Edition or Windows 2008 Server Enterprise Edition. For a Windows shop, Hyper-V is heavily discounted for IT shops with Microsoft's Volume Licensing.
From the IT management perspective, Microsoft's price breaks make the decision on picking a Windows virtualization solution difficult. Can the organization's IT applications run properly on Hyper-V, even given its technical constraints? Or are the technical constraints too limiting or risky for the business? There is no one right answer. However, it is a good idea to test both Windows virtualization solutions in the IT shop to make sure the virtual machine performance is adequate to run the business.
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