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The Greening of IT
12 How Companies Can Make a Difference for the Environment

Until widely accepted metrics become available, businesses should make
sure that the utility costs associated with their data center operations are bro-
ken out separately from those for other corporate facilities. In addition,
metering specific equipment racks or types of equipment such as servers can
provide valuable insight into which specific consolidation, virtualization,
and optimization projects will yield the best ROI going forward. The status
of energy-use metrics is the subject of Chapter 7, “The Need for Standard IT
Energy-Use Metrics.”

5. Implement Efficient Applications and
Deduplicate Data
Software and application efficiency can be significant for green IT. The
author has had a recent experience where the procedure for creating a data
warehouse report was reduced from eight hours to eight minutes merely by
changing the Oracle data warehouse search procedure. (For example, don’t
search the entire database each time when only a much smaller search is
required.) During the eight hours required to create the report, the large
ptg
server was running at near peak capacity. Sure, that type of significant appli-
cation inefficiency has been created and fixed many times over the history of
programming. But what about the cases where a few application efficiencies
can make an application run 20 percent faster? That 20 percent more-
efficient application can also result in 20 percent lower energy use. The steps
required to improve application efficiency by a few percent are often not easy
to determine; however, the added incentive of saving energy—while making
the application run faster—is a significant plus.
Data-storage efficiency, such as the use of tiered storage, is also significant.
Data deduplication (often called intelligent compression or single-
instance storage) is a method of reducing storage needs by eliminating
redundant data. Only one unique instance of the datum is actually retained
on storage media, such as disk or tape. Redundant data are replaced with a
pointer to the unique data copy. For example, a typical email system might
contain 100 instances of the same one-megabyte (MB) file attachment. If the
email platform is backed up or archived, all 100 instances are saved, requir-
ing 100MB storage space. With data deduplication, only one instance of the
attachment is actually stored; each subsequent instance is just referenced
back to the single saved copy. In this example, a 100MB storage demand can
be reduced to only one MB.