Hyper-V is Microsoft's answer to VMware ESX and other hypervisor based virtualization solutions. For those who are virtualizing Windows servers, Hyper-V presents a compelling Windows virtualization solution based on much lower cost and a feature set that's good enough for many Windows based IT shops.
Those who remember Microsoft Virtual Server should know that Hyper-V is a complete rewrite and is a different piece of software. Microsoft Virtual Server is a host based virtualization solution, which is too slow for a production enterprise environment. On the other hand, Hyper-V is a hypervisor based virtualization solution that's very well suited for high performance production environments.
Hyper-V CPU and I/O Performance
Hyper-V requires hardware assisted virtualization such as Intel VT-X or AMD-V which makes virtualization run fast. The consequence of requiring CPU based virtualization assistance also means Hyper-V will not run on old hardware and that it will only work on 64-bit Windows Server 2008.
I/O performance was independently tested by storage vendor Qlogic with results that show Hyper-V performed at 88% to 99% of native performance, depending on the storage subsystem used.
Hyper-V Quick Migration
With Hyper-V's Quick Migration, a virtual machine is suspended while it's being copied over the network to another physical server. The duration a virtual machine is down is short, but there is still downtime.
Guest Operating Systems Compatible With Hyper-V
The list of operating systems includes nearly all of the operating systems most IT shops are concerned about. Operating systems supported include:
- Windows Server 2008
- Windows Server 2003 SP2 R2
- Windows Server 2000 SP4 and Advanced Server
- Windows 7
- Windows Vista
- Windows XP Professional
- SuSE Linux 10
- Red Hat Enterprise Linux (RHEL) 5.2 and later
Hyper-V is Much Cheaper Than VMWare or Citrix XenServer
The reason to buy Hyper-V is due to cost, especially for a Windows shop. Windows Server 2008 Datacenter Edition costs $3,000 per CPU socket, regardless of the number of cores. With the Datacenter Edition, it allows for an unlimited number of virtual machines Windows Server 2008 and Windows Server 2003. If Microsoft Volume Licensing is included, the cost is essentially zero.
For an IT shop running Windows, the prime candidates for applications to use Hyper-V include Exchange, IIS, SQL Server, and Sharepoint. The virtualized environment would be supported by the same vendor as the applications. The cost of virtualization software cost is lumped in with Windows Server 2008, which would have been bought anyway.
Unless a Windows shop needs all of the features of VMware or Xen, the cost savings from buying a good, but not great solution is significant compared to the technically superior offerings from VMware or Citrix.
