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Reducing Power Use
Once you have an idea of how much power you’re using, it’s time to take steps. There are a
number of ways you can cut your electric bill. In this section, we’ll take a closer look at
some ideas that can help cut power use.

Data De-Duplication
The mantra of computer use has been (and likely will continue to be) “Back up your data.”
And that’s good advice. It’s like “Wear your seatbelt” and “Never play pool against a guy
named after a city.” It just makes sense.
But are we overdoing it? Although it’s never a good idea to hit the freeway without a
seatbelt or to play nine-ball with a guy named Cleveland, we tend to back up stuff over and PART II
over. Once is often enough. More than that is just wasteful and costly.
So-called “data de-duplication” is a tool for reducing storage and bandwidth consumed
from disk-based backup. By eliminating the need to constantly back up the same file over
and over again, backup storage consumption is reduced 10 to 50 times. Because less data is
sent across your network, overall bandwidth consumption is reduced by almost 500 times.
The obvious benefit is freeing up storage space, but there are energy implications that
affect your corporate ledger. Reducing the number of data copies reduces storage capacity
needs and storage power consumption. Further, once data storage has been reduced,
snapshots and other copies from high-performance disks can be shifted to lower-performance,
energy-efficient disks.
The benefit trickles down when you consider your organization’s remote sites. Because
less data is being replicated, money is saved because network traffic and storage capacity
are not being overused.

Virtualization
The biggest power draw to your IT infrastructure is from your servers. In and of themselves,
they can gobble up 50 percent of the power coming into your datacenter. The best way to
reduce this power usage is to reduce the number of servers you use.
“Madness!” you proclaim. “We have that many servers because we need that many
servers.”
Although you may have, in the past, needed that many servers to fulfill mission-critical
tasks, by consolidating several machines into one and through virtualization, you can wheel
out some of those watt-munching behemoths. This is illustrated in Figure 3-2.

NOTE We’ll talk about server virtualization and how to get your hands dirty doing it in Chapter 13,
when we discuss configuring the server and using applications such as Virtual PC and Microsoft
Virtual Server.

Data storage is another massive consumer of power. Direct-attached storage can account
for as much as 27 percent of your electricity bill. Direct-attached storage units fragment
where data is stored in the organization. Also, each device must consume its own power.
Clustering also involves identical hardware and operating systems to ensure a smooth
rollover in the event of tragedy. The costs add up, especially when one considers the cost of
the hardware and the power draw—especially from a largely unused device.