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One item that I have seen come up again and again recently with my customers is a mis-understanding of ESX and VM Server.  Particularly the performance aspects of both.  These are two entirely different products with entirely different goals that need to be kept in mind when comparing the two.

VM Server is the free server virtualization product from VMware.  It’s purpose was to help seed the market and get people more confortable and familiar with virtualization concepts on the server.  What better way to do that than give something away for free for people to play with!  VM Server is similar to VM Workstation/Fusion in that it runs on top of an OS; so from the ground up you have:

server hardware > operating system > VM Server > virtual machine.

This means VM Server inherets the same performance issues that the OS has.  It also means that it has to rely on the OS for a lot for the management of resources.  Net result:  the performance of VM Server will be impacted by the OS you are running it on top of.

ESX is the data center grade hyperadvisor from VMware.  It’s purpose is to provide virtualization for  business critical data centers.  ESX essentially doesn’t run on top of an OS.  You can think of it as a data center OS as it is the base layer for the Virtual Infrastructure set of products. Similarily, from the ground up you have:

server hardware > ESX > virtual machines

You can see immediately that ESX has eliminated the operating system level, this is the source of the performance gain that ESX provides.  It is running on top of the raw hardware.  It is truely a specialized OS with the sole pupose of virtualization.

One thing that VM Server and ESX share, is the engine to run a virtual machine.  This engine has lots of tricks built into it to manage the physical resources of the box and to distribute them efficiently to the virutal machines that need them.  Of couse, you still suffer from that extra piece of the base operating system under VM Server.  This is why you can have VM Server running with no VMs and still see it utilizing resources.  It’s doing the work of interfacing with the base OS for resource management even when no one is using the resources.

So, if you hear somone complain about their VMs are not performing very well ask them which product they are using.  If they are using VM Server, point them here.  If they are running ESX, then it’s time to dive into the typical operating system and application stack tuning/debugging routine.

(Disclosure: I currently work at VMware as a Solutions Consultant)

Today I introduced the VMW Launchpad.  A collection of information resources from or related to VMware.  Since starting at VMware as a Solutions Consultant, I have been collecting items that are frequently requested from my customers and others regarding VMware and our products.  I’ll be updating the Lauchpad as a reference source for those common items.  I will also be posting some personal write ups based upon my experiences.

And of course all these items, along with the rest of this blog, reflects my views and not the views of any company, employer, or group associated with me.

(Disclaimer: I am currently employeed at VMware as a Solutions Consultant)

There has been a number of announcements over the past few weeks in the area of Application Virtualization, most notably VMware’s release of ThinApp.  With the ability to wrap an application in a virtualization container and then run that virtualized application as a stand alone executable, virtualization has been taken to the next level.

As I have been talking to enterprises about application virtualization, a base understanding of why this is important is always needed.  The simplest example of where application virtualization can be used is when you think of the need to have two different versions of the same application.  Image you are a QA tester testing a web based application.  Usually, you verify that the web based application works with both IE 7 and IE 6 or now Firefox 2 and Firefox 3.  In the past, you had to have two machines (physical or ideally virtualized) with each browser installed since they can’t live together on the same machine.  Talk about overhead.  With application virtualization, each version of IE gets placed in the virtualized wrapper and becomes a standalone executable.  Allowing you to run both apps at the same time on the same machine.

Moving to a more complex example, think about virtualizing most of your core applications across an enterprise.  If each application is a stand alone executable, what happens when a user accidentally deletes one of the library files for the application?  First off, this wouldn’t happen because they are all placed in the virtualized wrapper.  But if it did, all IT has to do is tell the user to download the virtualized app again from a central repository.

The cost savings for IT administrators of the desktop can really start to add up.  These include:

• Less disk space requirements since the virtualized application is compressed
• Savings in admin hours just from not having to reboot Windows after an application is installed; virtualized applications don’t require a reboot to install, just copy to the machine and run it (or run it from a USB key).
• The elimination of the re-builds or re-installation of desktops due to user’s accidentally corrupting an application; the self contained virtualized apps can’t be corrupted like a natively installed one.
• A reduction in troubleshooting application conflicts since each application lives in it’s own virtualized world.

When you take each of these areas of time saving and extend this across 20k, 50k, 200k desktops the time savings starts to have huge impact to the efficiency of an Desktop IT organization.

Stay tuned as I get more real world examples…

(Disclosure: I am currently employed as a Global Accounts Solutions Consultant at VMware.)

Yesterday I spent half a day discussing virtualization strategies with a few CTOs from a $15B firm from the healthcare industry.  It was refreshing to see the same glint in the eyes of these CTOs regarding virtualization’s potential to revolutionize their data centers as I saw before joining VMware.  The key aspects of these discussions was how virtualization can help them reduce not only their capex but also their opex.  They also saw the potential that virtualization provides in the areas of increasing their service delivery times (provisioning new systems for customers in 2 hours instead of 2 weeks or 2 months like they are used to) as well as enabeling a new way of thinking about disaster recovery.

Like most IT executives, these CTOs knew about virtualization from the aspect of the hyperadvisor; the core of virtualization that allows you to run multiple operating systems on the same computer at the same time (with each operating system thinking it’s by itself).  This is just the start of the software computer revolution.  Now that you have isolated the OS down to just a bunch of files that can be moved between physical computers transaprently, you have the ability to provision a machine in a short period of time.  Create a base Virtual Machine image for each of your approved OS’.  Next copy that base OS to create another image for each of your general application types.  You now have a library of images that can copied within seconds to an existing physical machine, booted and viola, a provisioned server in minutes; substantially reducing opex.

Also, since the “data” that the enterprise is already backing up for disaster recovery now contains the applications and operating system, DR takes on a whole new meaning.  (and not just DR, but resource “load balancing”, server maintenance, data center migrations…pretty much all the maintenance work that IT has to do.)  You can take your old machines and deploy them to your DR site. Now use your existing data replication software to replicate the VM files.  When your main data center goes down, just turn on your VMs in the DR data center and back to business.  Sure, performance might not be the same, but the business is functioning; the key point of DR.  And since you used hardware that you already own, your capex is reduced.

“Cloud Computing for the Enterprise”.  That is what one of the CTO’s called virtualization.  As someone who has been living in the cloud for years on the Web 2.0, this is not a shocking way for me to think.  Cloud computing was easy for the web, where you had (or could build) apps out of standard web based (REST based) building blocks.  But for an enterprise architect who has to deal with complicated software packages from properitary vendors that process Billions of dollars in orders, this was a refreshing thing to hear.

Could this type of statement indicate that virtualization and utility computing has arrived for the enterprise?

I think that’s a safe statement.