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VMware ESXi vs Microsoft Hyper-V Server 2008


Queries the following Comparison is trying to Answer:


VMware ESX (i) 3.5 VS MS Hyper-V Server 2008

How does MS Hyper-V Server 2008 compare to VMware ESXi?

Advantages & Disadvantages of Hyper-V & VMware VI3i (V3.5)

What is better VMware ESXi or MS Hyper-V Srvr 2008? How?

Independent Unbiased Comparison MS Hyper-V Server 2008 & VMware VI3i


VMware ESXi VS MS Hyper-V Server 2008 Introduction:


Ok, decided on riding the virtualization boat and confused on the right product for your company. You are in the correct place as here we list the comparisons of most of the virtualization solutions. On this page we will compare Microsoft Hyper-V Server 2008 vs VMware ESXi 3.5, but other comparisons are available and you can choose them from the menu on the left panel. Not to confuse this comparison with VMware ESX vs MS Windows 2008 Hyper-V, VMware ESXi & Microsoft Hyper-V Server 2008 is the lightened version of both products. VMware ESXi is 32MB version of VMware ESX & MS Hyper-V server 2008 is a service core install of Hyper-V. Both products are lighter and hold a smaller code & Foot print from their full version. Both of these versions were created to increase the speed & decrease the attack surface of both products though it eliminate some features. If you are looking for a comparison between the two full fledge products then you should check the following comparison Microsoft Windows 2008 Hyper-V VS VMware Virtual Infrastructure 3.5


As both of these products (VMware ESXi & MS Hyper-V Server 2008) seems to be the future of the current virtualization products of each vendor & their current best secure version its worth reviewing how they compete. Below is a full fledge comparison of VMware ESXi & MS Hyper-V Server 2008.



VMware/EMC Microsoft



ITComparison Comments

VMware site is a bit easier to browse in regards of virtualization than Microsoft site due to the fact its their core business and they don't offer as much products to jam their site comparing to Microsoft.

Product Name VMware Virtual Infrastructure VI3i Microsoft Hyper-V Server 2008
ITComparison Comments It seems that VMware Virtual Infrastructure 3 is more attractive naming than Hyper-V due to virtualization being the new infrastructure of the DataCenter.
Pricing range paid product Free Free
ITComparison Comments Both Products are 100% free downloadable software. VMware reply to Microsoft free MS Hyper-V server 2008 by releasing thier VMware ESXi for free.
Primary usage Production Environment
  • Test and Development
  • Basic Server Consolidation
  • Branch Office Consolidation
  • Hosted Desktop Virtualization (VDI)
ITComparison Comments
























-: MS Hyper-V 2008 Server VS VMware ESXi :-

 VMware ESXi has been in the market for over two years. It had been pushed by VMware to be used in production & to replace their normal ESX servers in larger installation as its faster & have a lot smaller foot print which highly reduce the attack surface.


In the other hand, although Microsoft Marketing team has been bargaining about their MS Hyper-V Server 2008 & how it has a smaller attack surface & faster speed than their full fledge server they still don't seems to recommend it for primary production use. The below is directly quoted from Microsoft website (

===========Quote Start==============

Hyper-V Server 2008 only offers the most basic of virtualization features, making it ideal for:

  • Test and Development
  • Basic Server Consolidation
  • Branch Office Consolidation
  • Hosted Desktop Virtualization (VDI)

============Quote End===============

That will definitely deter most Enterprise Administrators from using MS Hyper-V Server 2008 in their primary production environment and force them to stuck with the bulkier & less secure version Windows 2008 Hyper-V. Our team believe MS should focus more on this lightened version to better success in the Virtualization Market.


Required General usage Host OS (if any) Infra v3:bare metal

No host OS required

Windows 2008 Server Core
ITComparison Comments






-: Microsoft Hyper-V  VS VMware VI3:-

Although MS hyper-V Server 2008 suppose to be the lighter & most secure version of MS Hyper-V offering, unfortunately its still has to implement a Windows 2008 Server Core for it to run. The Windows 2008 Server Core is installed while MS Hyper-V Server 2008 is installed. Though its worthy to mention that Microsoft had hardened & reduced the size of the Windows Server Core integrated into the Hyper-V Server 2008, but it still a general use operating system & not even beating the version of Redhat integrated in the full version of VMware ESX which VMware taking out in their lightened version VMware ESXi.

In the other hand, VMware ESXi has no operating system at all running beside its hypervisor. They had even got rid of their Service Console( A lightened & highly modified Redhat) which should be count as a plus to VMware in this comparison.

Unfortunately Hyper-V Server 2008 still have a larger surface for attack, viruses, & spyware to hit by keeping the Windows 2008 Server core as a part of it. It would be a great enhancement if MS can create a specialized Hyper-V Kernel than relaying on their Windows Server Core to drive their virtualization Solution.

Management tools VI Client

Virtual Center 2.5

Hyper-V Manager

SCVMM 2008

ITComparison Comments

Both Hyper-V Server 2008 & VMware ESXi has a basic management tool coming with it for free. VMware offer VI Client  & Microsoft offering Hyper-V Manager. VI Client has a nice advantage on Hyper-V Manager that you can install it on several operating systems, where Hyper-V Manager can only be install on Windows Vista SP1 or Windows 2008.


Both as well offer an advanced management software which add advanced features to its product. VMware offer Virtual Center, where Hyper-V offer SCVMM 2008. The main disadvantage of SCVMM 2008 for MS Hyper-V Server 2008 that it can't add the advanced features of the Windows 2008 Hyper-V version (Quick Migration, MSCS, & more) to MS Hyper-V Server 2008. In the other hand, VMware Virtual Center are able to provide VMware ESXi with all the advanced features that the full version of VMware ESX can provide, but license will be required for some of it.

Support resources High Medium
ITComparison Comments

Microsoft might have more support resources than VMware,

but not when it comes to virtualization, though they are investing into that direction.

Supported Guest OS

- Microsoft WindowsNT4.0   


 - Red Hat Enterprise 2.1/3/4


- Red Hat Linux Advanced Server 2.1                                  

- Redhat Linux 7.2/7.3/8.0


 - SUSE Linux Enterprise Server


- SUSE Linux 8.2/9.0/9.1/9.2


-FreeBSD 4.9/4.10/4.11

- NetWare 6.5/6.0/5.1      

- Solaris 10 for X86          

- Vista

- Windows 2008

- Windows 2003           Standard /Enterprise SP1/SP2/R2

64-bit + Virtual SMP (Supported

in Production) 

- MS Windows 2003/2008

- MS Windows 2000 Server/Advanced Server SP4

- Windows XP SP2/SP3

- SUSE Enterprise Linux Server  

  10 SP1/SP2

ITComparison Comments

Its obvious that VMware has production support for many more OSs than Microsoft.  Actually supported guest operating systems in Microsoft Hyper-V Server 2008  is very limited. In addition, not all supported OSs on Hyper-V will run with optimal speed on it. This is due to Hyper-V needs for the virtualized OS to understand its running in a virtual environment to perform well on Hyper-V, which is not even the case with windows 2003.

Linux Support Support most Linux version available today. - Only SUSE Enterprise Linux Server 10 SP1/SP2 is totally supported

- Xen supported versions of Linux is planned to be supported. They should run by now, but with modification and not supported.

ITComparison Comments

Its obvious at the moment that Hyper-V is still lagging on Linux support, where VMware support running most version of Linux without the need to modify it, Hyper-V still only officially support SUSE Enterprise Linux Server 10  SP1/SP2 at the moment. Other Linux versions that have Paravirtualized Xen Kernal should run at the moment, but still not officially supported. Even with the limited version of Linux being supported by MS Hyper-V it still not that easy to setup. To illustrate the required steps to setup Linux on Hyper-V read below:


Microsoft Hyper-V provides Integration Components for Linux OSes, It would been acceptable if the Integration Component for Linux OSes were straight forward to setup but it require many complicated steps and what worse you have to do the same steps over and over again for every Linux virtual machine including the following:

1- Manual installation of Xen Kernel.

2- Excute a seperate script that modifies the Linux bootloader 

    configuration to allow the use of Microsoft Hypercall adapter.

3- Run a perl script to install the Integration tools and paravirtualized drivers.


Note: If you want to see a full step by step of how SUSE is install on Hyper-V look at SUSE Installation on Hyper V at Virtualization Team Blog


Its clear that setting up Linux on VMware is way easier and cleaner than Hyper-V at the moment, but Microsoft might change that in future releases.


Further More, Hyper-V still does not support the 2nd generation of Paravirtualization for Linux (paravirt_ops / VMI (Virtual Machine Interface)). Method used to support Paravirtualization with Linux in hyper-V increase the maintenance of Linux OS as the administrators will have to keep up with two kind of kernels for virtualized & Physical servers. In addition, they have to recompile their Linux kernel in order for it to work. In the other hand, VMware are already offering support for paravirt.



- Higher Performance

- More virtual Machines per hardware as it support memory over commitment.

- Perform well with Operating systems that understand its running in a virtualization environment currently Windows 2008 & SUSE

- Fewer Virtual Machines per hardware

- Domain 0 is a bulky windows 2008 & even the Server Core installation can waste a good amount of resources.



The performance advantage of VMware is related directly with its smaller foot print than Microsoft Hyper-V Server 2008. VMware ESXi is totally using 32MB, where MS Hyper-V Server 2008 is larger than 2GB. In addition, memory over-commitment & Memory ballooning help VMware run more virtual machines without sacrificing performance.

64-bit Support Has full support for most of the 64-bit Operating Systems. Support Windows 64-bit Operating Systems.
ITComparison Comments This is an obvious advantage of MS Windows Hyper-v over MS Virtual server which did not support any 64-bit guest OS, but still lag behind VMware on this one as well.

Live Migration



High Availability



Dynamic Resources



Storage VMotion (SVMotion)



Cluster File System


Network Teaming









































Dependent on the network card manufacture.



 Although Microsoft had tried to compete with some of these features in MS Windows 2008 Hyper-V they dropped all of them in their slimmed version MS Hyper-V Server 2008. To find out how MS Windows 2008 Hyper-V compare to  VMWare ESX offer check out our comparison for the blown version of each product VMware ESX vs MS Windows 2008 Hyper-V. Though  Below is a quick overview of each of these features.

VMware VMotion:

VMware VMotion is real Live migration for virtual Machines between hosts. It give VMware users the ability to move their virtual machines from one host to another host with zero downtime.

High Availability:

Virtual Machine on a failing VMware host will get restarted automatically on another host.


VMware will re-distribute its virtual Machines between VMware host in away that produce best performance for the VMs.

Storage VMotion:

SVMotion is a new feature of VMware VI3 where the entire disk files of a virtual machine can be moved from one storage array to another without affecting the operation of that Virtual Machine. This mean VMware VI3 users can avoid downtime for their virtual machines when they need to carry a storage maintenance. It means as well they can easily upgrade or move to a new storage without the need for a down time. This feature has no equivalent in MS Hyper-V at the moment, which mean downtime for storage maintenance can't be avoided.

Cluster File System:

VMware VMFS is a cluster file system, which give vmware ESXi a great flexibility & a key factor in most of the advance features VMware offer. In the other hand, Hyper-V Server 2008 still use the same non cluster File System Windows use NTFS which make it lag in functionality behind VMware.

NIC Teaming:

VMware offers a network card independent NIC Teaming, where Hyper-V is dependent on the network cards teaming driver & Software offered by the network card vendor.

Please note: some of  these features will require a license to be used with VMware ESXi.

Virtual Machine support SCSI disk Boot Yes No



MS Windows Hyper-V still does not support booting virtual Machine from Virtual SCSI disk. It only support it from Virtual IDE disk which will highly slow the performance of these virtual machines. It is not clear yet when Hyper-V will support booting virtual machines from virtual SCSI disk as no announcement on that have been made. If MS does not come up with boot from virtual SCSI then they are risking their product of a very bad performance lag behind VMware which has that capability.

Online Backup VCB (VMware Consolidated Backup)  Live Backups with VSS



VMware VCB is a great backup advantage as you can with it take live backup (image) of running virtual machines without affecting the performance of the host neither the virtual machines performance, where with MS Hyper-V that still seems to depend on the host capabilities using the Volume Shadow Copy Services (VSS) to enable you to take Live Backups of running virtual machines in terms of snapshots, but still affect the Hyper-V Host performance while the backup is running.

Max virtual Machine Specs

64GB of RAM


64GB of RAM




Although Microsoft has been good in keeping up with numbers for marketing, still VMware can offer a better specs virtual machines for most Operating systems beside windows 2008. At the moment, 4 virtual CPUs are only recommended on Windows Server 2008 with Hyper-V. Its not even recommended to use more than one virtual CPUs with Windows 2003 at the moment, but this hopefully would be resolved with future releases. The following quote is directly from Microsoft Hyper-V release note:


          =====From MS Hyper-V RC release note Begin=====


Configure the virtual machines as follows:

For the guest operating system, install one of the following:

  • Windows Server 2008 RC1 with Hyper-V Beta, with a maximum of 4 virtual processors. No other release of Windows Server 2008 is supported with this release of Hyper-V.

  • The Windows Server 2003 operating system, with a maximum of 1 virtual processor. You can install either a 32-bit version or an x64-based version."


        =====From MS Hyper-V release note End=====


Special Hardware Requirement Require supported SCSI or SATA controllers.

A supported Hardware List is provided.

x64 based processor computer hardware-assisted virtualization, and hardware data execution protection (Intel VT or AMD-V) is a must.



It seems Microsoft has forgotten again that many companies have some older hardware that does not run 64-bit and would like to virtualize their environment. MS Hyper-V force companies to obtain a newer more expensive hardware to be able to virtualize. VMware in turn had their own hardware supported list, but most server from well-known manufactures in the market today are supported, and will support all features offered by VMware like clustering which requires a special support statement for Windows 2008 Hyper-V if used, but as mentioned earlier MSCS is not even supported in Hyper-V Server 2008.

Other Related Comparisons:


Windows Server 2008 R2 Hyper-V VS VMware ESX 4.0

Microsoft Windows 2008 Hyper-V VS VMware ESX 3.5

Xen Server Enterprise VS VMware Virtual Infrastructure 3

Microsoft Virtual Server 2005 R2 VS Xen Server Enterprise

Microsoft Virtual Server 2005 R2 VS VMware Virtual Infrastructure 3


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