Can you save money by converting from a physical to a virtual infrastructure? Yes. Can you do it without spending any money? No. Can you do it without spending more than you would on conventional architecture and technology? Definitely.
The truth is that saving money with virtualization is possible, but the all-too-common lie of omission is that you have to choose your technology carefully.
Past articles have looked at how converting your current infrastructure to virtual machines can save you a lot of money. Here is the story's other side the how much it could cost you side.
Starting from Scratch
If you don't already have suitable hardware for making the switch to a virtualized infrastructure, you'll need to purchase it. A well-equipped* Dell PowerEdge 2950 III costs from $11,000 to $13,000. Add in the cost of VMware ESX** on that system and you're up to about $26,000. Oh, you'll need two of those systems with VMware ESX for any kind of high-availability setup.
You'll save $9,000 per system by going with VMware's "free" ESXi product, which brings the price of each system to $17,000. This option still includes the 4-year support option for ESXi.
By using the very free Citrix XenServer, also available from Dell as an add-on, you'll save an additional $4,000. If you're following along with a calculator, each system now costs $13,000. And that's hardware only.
These prices assume you have network attached storage or a backup solution already in place for your physical systems to use. If not, you'll need to pony up another $5,000 or so to add storage space for all those virtual machines.
Migrating Physical to Virtual
VMware offers its free physical to virtual machine conversion tool, VMware Converter, to make life easier and to save you the time of re-creating every Windows system as a virtual machine. Yes, it's Windows only. For Linux, or other operating systems, you'll need to create virtual machines that represent your physical ones and then migrate your applications to the virtual machines.
Migrating existing applications from physical to virtual machines can be tedious and frustrating. Be sure to factor in the time and expense of migrating your applications during the planning phase of your conversions.
Putting Numbers to Paper
If your current infrastructure is approaching the end of its useful life, then adding up the costs of replacement will convince you that virtualization is a big money saver especially if you use the many free options available to you. However, if your systems have a couple of years to go, virtualization might be too expensive a choice, even if the hypervisor software is free.
The $13,000 systems mentioned above have the capacity to replace eight to ten (or more) physical systems with a high level of performance and reliability. If you replace only eight physical systems, the cost is $1,625 per system. Is it possible to replace old hardware with new ones for that price? Adding in the cost of VMware's ESX product would bring the replacement cost to $3,250 each. Does that still sound reasonable to you?
I by no means intend to paint a bleak picture of virtualization or the conversion to it but it is important to go into the process with a realistic picture of what's in store for you. Virtualization is a frugal technology choice but requires, as you've seen, significant investment. Often, virtualization is more of a "back end" savings technology. You'll save money on power consumption, cooling, management, deployment and maintenance, but don't be fooled by the hype that tells you otherwise. If after calculating the pros and cons of conversion, ask yourself this one question, "Can I afford to save this much money?"
Have you done any ROI calculations to see if virtualization has saved you any money? Use the Comments section and let me know.
* 32GB RAM, Quad Core, RAID 5 1TB storage, redundant power supplies, quad GE Ethernet, UPS.
** VMware VI 3.5, Enterprise 2 CPU, 4Year Subscription.
Ken Hess is a freelance writer who writes on a variety of open source topics including Linux, databases, and virtualization. You may reach him through his web site at http://www.kenhess.com.