So now that you know what virtualization is, the next question is why is it so hot? The simplest answer would be economics. Virtualization helps businesses make more efficient use of their IT assets. Rising energy costs have seen data center power bills rise by over 200% in the past few years in some locations. The physical machines themselves have become more powerful, so powerful that many of them are running at very low capacity. It makes sound financial sense them to find better ways to use the resources available than to buy more resources.

According to Gartner Research, data center power and cooling problems will get worse during the next 10 years as energy bills continue to rise.[1] The amount of money that is being allocated to energy bills is having a major impact on budgets not only in IT, but across the entire business. As energy prices have risen over the past few years, computers have been on a steady power diet. Even machines that make more efficient use of power are still putting out massive amounts of heat that must be cooled. As technology has improved, and computer systems have shrank, the amount of heat being put out has increased as more circuitry is packed tighter together. The amount of energy required to power and cool three racks of 10 servers each is equivalent to the amount of power needed to light 4-5 residential homes.

Virtualization helps address rising power costs. Traditionally, many servers hosted one application. However, as technology improved and those servers became more powerful the single application could be using less than 10% capacity of the server even at peak demand. That means that 90% of the server is not being utilized. This represents a huge inefficiency.

By being able to load multiple OSes onto a box we are now utilizing the wasted capacity with little to no additional energy costs. For example, if we have 5 servers that are running applications that consume 10-15% of the total system resources each, we could consolidate those 5 servers into 5 virtual sessions residing on one physical server that makes use of 75% of the total system resources.[2]

If in our example above we assume that each server is pulling in 200W of power, and each server is running 24 hours a day, 7 days a week for a full year then we are using 8,760 kWh[3] per year. If we assume that energy costs are $0.08 per kWh then in a typical year to power the 5 servers we will spend $700.80. Keep in mind that this figure does not include cooling costs which can often be more expensive than powering the servers.

Now if we take the same 5 servers and consolidate them onto 5 virtual sessions residing on one physical machine our costs are reduced by 80%. The energy cost to power our server falls to $140.16 per year and we should expect o see a similar decline in our cooling costs since we are now putting out 80% less heat that needs to be cooled.

The economics of virtualization when it comes to energy savings speak for themselves!

While virtualization is helping us reduce our energy costs, it is also helping us reduce the square footage of our data centers. This can be particularly important when IT operations are located in dense urban areas where the price per square foot of office space is significant. By making efficient use of hardware through virtualization consolidation it is not unrealistic to expect to see your square footage needs for the data center drop by 25% or more.

Virtualization is also helping find efficiencies for backups, redundancy[4] and disaster planning. Traditionally if a company wanted to have 24x7 99.999% uptime they had to invest heavily in separate data centers and hot standby systems[5]. It was not unusual to see companies having a full, exact copy of their data center located at another facility. While necessary for business continuity, it also was a huge drain on IT budgets to have that hardware sitting idle.

Through virtualization techniques it is now possible to create backup systems to prepare for almost any emergency in a cost effective manner. By creating virtual images of servers they can be brought online just about anywhere, regardless of what hardware is available. Thanks to new virtualization technologies that are coming into the marketplace, such as VMWare’s VMotion[6], it is now possible to have near zero downtime even when an unexpected system failure occurs. Even better, this zero downtime is achievable at a fraction of the cost of maintaining separate physical systems.

Energy costs savings, physical space savings and hardware savings – three of the big cost savings factors that are making virtualization one of the hottest trends in IT today. Keep in mind that there are numerous other benefits to virtualization besides the cost savings. These include being able to have dedicated development environments, the ability to support legacy systems when hardware may no longer be available and the ability to migrate software to new systems with ease. We’ll touch on each of these a little more later on.

[1] Gartner Research, “Data Center Power and Cooling Scenario through 2015”. March 14, 2007

[2] Virtual host systems, those that run the virtual systems, are never pushed to their full capacity. This is because you must account for overhead or the amount of resources the virtual machine manager is taking up to run the virtual sessions.

[3] Kilowatt Hours

[4] Having the ability to fail IT systems from one location to the other in the event of downtime or other emergencies.

[5] A hot standby system is one that is running and able to take over almost instantaneously.

[6] A method by which virtual servers which are up and running can be moved to different machines with zero downtime.