What is better MS HyperV or VMWare ESX?

I'm looking for a list of pros / cons to compare MS HyperV against VMWare ESX for Virtual Server hosting.

Solution 1:

This is probably one of the best articles I've read so far comparing Hyper-V and VMWare ESX:

How to Correctly Explain the Architectural Differences Between Hyper-V and ESX

Update

The link above no longer works so here's WayBackMachine's last known snapshot:

http://web.archive.org/web/20090418212623/http://www.realtime-windowsserver.com/virtualization/2009/04/how_to_correctly_explain_the_a_1.htm

Wayne (see comments below) also suggested a couple of alternatives.

The first is a response to the original and now defunct article:

Updated: Reaction to: “How to Correctly Explain the Architectural Differences Between Hyper-V and ESX”

The second article has unfortunately had the video removed from YouTube.

Solution 2:

As one who has used both (and continues to), I would recommend Hyper-V, especially if you are primarily a Microsoft shop. We have migrated over 25 virtual machines from VMware to Hyper-V using SCVMM, and the migrations have been flawless. We needed more memory, as currently Hyper-V does not support memory compression/overcommit yet, but memory is cheap right now and Hyper-V has this feature comming soon.

VMWare also has live migration, but we have not seen a need for this. This feature is coming in the next release for Hyper-V

Hyper-V manager is fine if you have just have a couple of VM hosts, but SCVMM adds a number of useful functions, including libraries and combined view of VMware and Hyper-V hosts.

We will continue to use VMware as one of our servers is old and supports 32bit only, and we get some VMs from our clients. But all our new VMs are created using Hyper-V.

We have also been using SCVMM, and have created libraries of our common configurations. Provisioning a new VM, including naming and joining to the domain is all automated. We are looking to further automate using Powershell, see: http://msevents.microsoft.com/CUI/WebCastEventDetails.aspx?EventID=1032409528&EventCategory=4&culture=en-US&CountryCode=US

Overall, features, ease of use, and cost lead us to move to Hyper-V from VMware.

Solution 3:

The most direct comparison is VMware ESXi vs Microsoft Hyper-V Server 2008:

VMware ESXi

Free download
Lots of downloadable Virtual Appliances that you can install and start using right away
Memory Overcommitment for better efficiencies and guest consolidation
Broad support for Windows and non-Windows guest operating systems (10 Windows versions, 16 Linux versions, 2 Novell Netware versions and 2 Sun Solaris versions)
Uses the clustered/designed-for-virtualization VMFS (Virtual Machine File System)
Clear upgrade path to VMware vSphere/vCenter for additional "Enterprise" features (VMotion, High Availability, Fault Tolerance, Distributed Resource Scheduling, and more.

Microsoft Hyper-V

Free download
Native support for Volume Snapshot Service (Shadow Copy)
Supports 64-bit and 32-bit versions of Windows Server, 32-bit and 64-bit Windows Vista and Windows XP Professional, SUSE Linux Enterprise Server 10 (32-bit and 64-bit) [source]
Uses the same management interfaces (command line, PowerShell, remote console) as other Server Core instances
Uses standard NTFS partitions, which can be a plus if you're in a Windows environment
Microsoft Hyper-V Server 2008 R2 (currently available as a Release Candidate) will feature Host Clustering and Live Migration (similar to VMware's vMotion technology) - Features not available with the standalone VMware ESXi product.

Ultimately, I think the decision comes down to your use case for virtualization:

If you're in a Windows environment and primarily interested in server consolidation, Hyper-V seems like a good fit
If you're in a Linux or mixed-OS environment, VMware ESXi will likely offer better support for your guest operating system
If you're interested in consolidation plus mature high availability, disaster recovery, etc., ESXi combined with VMware vSphere are currently your best options (with additional costs, of course)