In a big data center where hundreds of servers fill multiple racks, the meter is always running on the operating
costs for your power consumption.
It's expensive not only to power these servers but also to pay for the energy needed to run your air conditioners and other cooling systems to keep the servers cool. A few simple tips on data center power consumption can help reduce those bills.
Know what you're using
To develop an efficient power usage policy, the first step to take is to measure the amount of power your data center uses. This goes beyond calculating the total amount of kilowatts per hour the servers and peripherals in your data center are using, and also it goes further than the energy bill.
To determine your power needs, you have to know which device is using a certain amount of power at a particular time. To that end, a power equipment calculator can be a great help. The American Power Conversion Corporation has some great tools that help calculate the load for different kinds of data centers.
Virtualize as much as you can
You might have heard this before, but it's true: Virtualization is a great help in optimizing the usage of physical servers. On current server-grade hardware, a small company's Web server often utilizes less than 10% of its system resources. That means that on the same hardware, you could run at least eight of these small Web servers. To do that, you need virtualization.
For more on power consumption
Get more tips from the power and energy guide
If you need to create many virtual machines that run the same operating system, consider using container-based virtualization. In container based virtualization, you start with just one operating system kernel on top of which many isolated virtual machines are running.
Linux-based LXC, or Linux Containers, is an emerging technology that can double the amount of servers you can run on the same hardware. As an additional benefit, most virtualization solutions offer power management as well; virtual machines are placed on hosts in an optimal way so that in some cases entire hosts can shut down if their services aren't needed at that moment.
Consider using microservers
If you cannot virtualize because of special requirements made by your customer or by the vendor of the applications you want to run, you could consider using a microserver. A microserver is a minimal server that is made to be used for small workloads. The advantage of using a microserver is that you'll also have small power consumption. Major server vendors such as Dell and HP are currently offering microservers.
Choose your data center location wisely
Now that most countries are connected with very fast Internet, it doesn't matter where you build your next company data center. So it wouldn't make sense to build it in the hot climate of, say, the California desert. You might as well build your data center in a colder region. If the outside temperature is low, you can use that to cool the air in the data center and you don't have to use the air conditioning at full capacity. Climate control makes up for about 50% of total power consumption in most data centers, so there are huge amounts of money to be saved if you can cut costs significantly on air conditioning.
Power-optimize your services
Do you know which of the services on your server are responsible for which part of the power use on that server? In some operating systems, it's easy to find out. Linux, for example, offers the powertop utility that gives a real-time overview of power consumption on your server. By using it to analyze your server, you might find out that there are some services using large amounts of power that you don't even really need. Powertop will show you what services they are, which allows you to switch them off if you find out that some services that you don't really need are responsible for using too much power.
ABOUT THE AUTHOR: Sander van Vugt is an independent trainer and consultant based in the Netherlands. He is an expert in Linux high availability, virtualization and performance, and has completed several projects that implement all three. He is also the writer of various Linux-related books, such as Beginning the Linux Command Line, Beginning Ubuntu Server Administration and Pro Ubuntu Server Administration.