Server Virtualization

Sorry to all my book blogging followers, putting on the IT hat today.

The question has been ask many times, “Which hypervisor is the best to use?”

Some give the whitty answer, “The one you like to use?”

That actually isn’t far from the truth as we will explore. There are three major players in this field, four if you include Virtual Box. They are VMWare, Citrix and Microsoft. Having used all three, these are the one I will explore (apologies to the Virtual Box fans in the audience…)


VMWare

The most expensive solution that I have seen is VMWare (they are working on their pricing model). VMWare has its free solution, ESXi – which is limited in its functionality, i.e. no vMotion, no HA (for more information see: http://blogs.vmware.com/esxi/2009/06/esxi-vs-esx-a-comparison-of-features.html). Once you start adding features that you require you actually see the true cost of VMWare. If ESXi suits your needs then go for it, its free.

From what I hear (sorry haven’t experienced this) VMWare is very good on the support side once you have purchased their product, and their forums are helpful if you are using the free version.

So why do so many people buy VMWare? Part of the reason I believe is that many admins will virtuallize all of their servers with the free version, and then discover they need a feature and must upgrade. Because they are already running on ESXi, they stay on that platform, rather than do the work required to switch to a different platform.

VMWare cost calculator: http://www.vmware.com/technology/whyvmware/calculator/


Citrix

Citrix XenServer, this is the platform I am currently using.

Xenserver has all the same essential features as VMWare, yet I personally find it easier to use and manage.  All you VMWare admins don’t throw stones, I said its my opintion. I have the Advanced License, with mutiple servers in a HA Pooled environment. This pooled environment connects to multiple sans for VHD storage.

On the support side, I have had many issues with Citrix. They require you to buy a support package with them. The forums have been useful however. Just like VMWare, there is a free version of XenServer which you can use.

Between the two of these, I would say download the free versions and test both – see which you like.

Xenserver cost calculator: http://www.citrix.com/English/ps2/products/subfeature.asp?contentID=2316476


Hyper-V

Hyper-V is microsofts entry in the the VM world running on Server 2008 R2. The preferred install is to a stripped down Core configuration. There implementation of VMotion and XenMotion is Live Migration (don’t be fooled it isn’t the same thing).

Multiple Hyper-V servers can be managed using Microsoft Virtual Machine Manager which is a nice utility. For a pure Microsoft shop, this is not a bad option for virtualizing, however you much understand Microsoft’s licensing model. Hyper-V is easy to use, the one thing I would suggest is setting a logical default location for all the files.

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