Hyper-V was originally launched by Microsoft in July 2008 as an update to Windows Server 2008 and is now available as a stand-alone product (Microsoft Hyper-V Server 2008 R2) or within versions of Windows Server 2008 and Windows Server 2008 R2. Hyper-V can also be installed on the pared down Windows Server 2008 Core versions. These systems provide a much smaller server footprint but no local GUI management.
Prior to the release of Hyper-V, Microsoft had gained experience in server virtualization after purchasing the Virtual PC software from Connectix. This was released and is still available as Microsoft Virtual Server 2005 R2; the history of both Hyper-V and Virtual Server is evident in their use of the same VHD disk format.
Although Microsoft doesnt have the same length of experience as VMware (their first product, VMware Workstation was released in 1999), could Hyper-V be a better choice than vSphere for some companies?
Today, standalone Hyper-V Server 2008 (R2) is available for free download from Microsofts website. For customers who have already purchased a version of Windows Server 2008 (R2), Hyper-V is automatically available as a feature within the product.
We shouldnt forget that both VMware and Citrix offer free versions of their products too. However in both cases, certain features are not available with the free releases.
For example, more advanced deployments may want to make use of features for high availability. With vSphere, vMotion (which enables the migration of guests between physical servers) is not available in the free releases; Hyper-V currently offers Live Migration (an equivalent feature) for free.
vSphere is licensed at four levels in addition to the free version. These are Standard, Advanced, Enterprise and Enterprise Plus. Pricing is based on physical processor and shown below. These prices are list and taken from VMwares website on February 2011.
vSphere Standard with 1 year production support - $1318.00
vSphere Advanced with 1 year production support - $2806.00
vSphere Enterprise with 1 year production support - $3594.00
vSphere Enterprise Plus with 1 year production support - $4369.00
These costs dont include any licenses for guest operating systems. This compares to list prices for releases of Windows 2008 Server:
Windows Server 2008 R2 Standard - $1029.00
Windows Server 2008 R2 Datacenter - $2999.00
The 2008 DataCenter license includes the rights to run an unlimited number of virtual instances of the Windows 2008 operating system at either Standard, Enterprise or Datacenter versions.
While direct comparisons arent truly possible, it can be seen that Microsoft is aiming to make the cost of using Hyper-V extremely attractive to customers who already use their Datacenter products, and that Hyper-V Server 2008 R2 provides a high level of functionality for no charge.
Clearly cost isnt the only factor in choosing a software product. Available features score heavily in determining whether a virtualization solution meets requirements.
Its true that Hyper-V is feature-lite in comparison to vSphere.
Hyper-V with the R2 release represents only the second iteration of the hypervisor, whereas VMware has reached version 4.1 of vSphere, with a new release expected later this year. However Microsoft is committed to adding new features and the SP1 release of Hyper-V Server 2008 R2 and Windows Server 2008 R2 have now been released to manufacturing (RTM).
This version will add Dynamic Memory and RemoteFX features (advanced memory management and graphics improvement features respectively), bringing performance improvements and making Hyper-V more suitable for VDI (Virtual Desktop Infrastructure).
Of course Hyper-V offers all the standard virtualization features. Hyper-V Server 2008 R2 supports up to 384 virtual guests, enables snapshots to be taken and, with the R2 release, provides both Live Migration and Host Clustering.
Live Migration is similar to vSphere vMotion in that it allows a virtual guest to be moved between physical servers without any downtime or disruption to the end-user experience. Previously, migrations could only be achieved with quick migration where a guest was paused for the time it took to transfer memory between servers. It is worth noting that vMotion is not included in the free version of vSphere (Hypervisor).
Host Clustering uses Cluster Shared Volumes to vastly improve the ability to fail over individual guests between Hyper-V servers in a multi-node high availability configuration. Clustering is not available in the free version of vSphere.