“Is it Real or Memorex?”
There’s a similar reality check going on over all the virtualization myths that are causing many businesses to ask if virtualization and cloud are worth the hassles.
In this post we’ll dive into six “Virtualization Myths” I have seen first-hand over the years.
1. “Virtualization Saves Money!”
This myth gets everyone, but in my experience, it is “Busted!” Why do I say “Busted?”
Because it will take years before your administrators, engineers, and environment are running efficient enough to cut CapEx and OpEx, enough to reduce TCO and improve ROI.
The truth is:
In the beginning for every reduction in spending, there will be additions of spend.
For example, you many reduce your physical hardware cost which will reduce a number of other costs associated with data center (ports, cooling, space), however, the increase in software licenses, both for VMware and tools will increase to offset the savings.
There will always be something to add for something removed, which leads to virtualization myths number two on leveraging.
2. “I can Build 100s of Virtual Servers on One Physical Server!”
For the record, this is technically true. Unfortunately, the VMs will perform poorly and in some cases be so bad that your users and developers will complain and become frustrated.
This myth is commonly believed and spread by salespeople that want to sell you something.
The truth is:
Virtualization does work and can support multiple VMs on one physical server, but there is a point where too many VMs have been created and the performance hit is not just on one VM, but all the VMs hosted on that server. Trading VM density for performance is not advised – “Busted!”
3. “Oversubscribing Resources is a Best Practice!”
Wrong again. Yes, you can oversubscribe memory, CPU and even storage by using thin provisioning and ballooning, but I don’t see it as a best practice and everyone is not doing it.
In fact, many top VMware engineers actually suggest the opposite, and have standardized their provisioning of virtual servers on a 1:1 resource ratio, which basically means: 1 GB of physical memory installed to 1 GB of memory assigned, or 1 GB or storage installed to 1 GB of storage assigned.
CPUs are slightly easier to deal with and can be leveraged easier, but even this has its drawbacks which you will find after doing it enough. “Busted!”
4. “Virtualizing Is Easy!”
If all your planning to do is virtualize enough servers to fill one host, yes it is easy. Just deploy VMs until it runs out of memory, CPU or disk space and stop…
I agree that is very easy to do, and you can even find free VMware, XenSource, KVM software to do this.
The truth is:
The minute you start building more hypervisor hosts, “easy” goes out the window and you have just turned your single point of management host into a complex environment that will start requiring special software and management tools.
At this point, you will require more servers, which will require more hardware, which will become more complex, which will require more tools that are no longer free, which will require more expertise, which leads us to the next virtualization myth.
5. “Anyone can Do It!”
I’ve managed multiple virtualization teams and environments, and this virtualization myth bothers me the most because it is totally false – Busted!
There is a big difference between an accountant installing a free edition of VirtualBox on his home desktop versus running VMware ESXi with HA clustering and shared storage that is properly supported and managed.
The truth is:
Just updating VMtools after a major ESXi upgrade on 10 or more hosts is complex enough to send the average system admin complaining because of all the reboots, approvals and QA work it will cause him to organize.
Not to mention most system administrators won’t know what they don’t know about virtualization best practices for the next 2 – 3 years. And even that’s not long enough because VMware keeps adding products and features that require constant training and hands-on trial and error to learn, which leads me to my final virtualization myth.
6. “Virtualization Reduces Staffing Requirements!”
In a small operation, this may be true if you’re leveraging one or two admins to do it all on a few big hosts.
But, there is a tipping point where you will start trading quarters for dollars, which means higher TCO.
The truth is:
Even in a small Windows OS run business that handles their own server builds for Exchange, SharePoint and services such as AD, DNS, and security, it can be a lot of work for two admins.
Now throw in ESXi and a small NAS, and complexity just went up 200 – 300% if you plan to use shared storage (datastores), and other VMware features or products.
One or two people will not have the cycles to do all the support, maintenance and operation duties that will go undone and eventually this will cause outages and waste.
Multiply this scenario by the factor of 10 or 20 and you now need more staff to do all the duties of networking, security, hardware, infrastructure and support for your DEV, QA, and production virtual environments.
And, if you’re anything like everyone else, you’ll want to consolidate, automate, standardize and test cloud solutions, which will require higher level scripting and development skills.
My team was never large enough or had the right expertise, to do all the projects they were being assigned. “Busted again!”
I could just as easily have written a post on the “six benefits of virtualization” and listed all the Pros, but I’ll leave that for another post and finish my point on Virtualization Myths.
Virtualization is like marriage, you need to go into it with your eyes opened and know the risks because on the surface it looks cool, fun and sexy!
Finally, once you start down the virtualization roadmap, it can be hard to keep track of what’s coming next…
Almost every day you will add something new to the roadmap that increases the scope and is supposed to make managing the complexity of virtualization easier, but unfortunately will never really add value because nobody has time to fully configure it, or because there’s one more license upgrade it requires for that feature to work…
Do you have virtualization myths to share with VM Install, please comment?