Page 72 - How Cloud Computing Is Transforming Business and Why You Cant Afford to Be Left Behind

MANA GEMENT STRATEGIES F O R THE CL OUD R EV OL UTION

The real secret of the cloud’s economies of scale, elastic
operation, and smooth availability to remote end users is not
just a big data center composed of PC parts, the use of Web
services standards, or the automated ability to balance work-
loads. It’s primarily virtualization.
There is no definition of a cloud—not even my own in

Chapter 1—that requires the servers in a cloud data center to
be virtualized, but nevertheless, in the long run, no public,
multitenant cloud is going to be competitive without it. Ama-
zon Web Services’ Elastic Compute Cloud (EC2), the leader
in cloud computing, relies on virtualization. The workloads
running in it are based on Amazon’s version of the open
source code Xen virtual machine. But what is virtualization?

Virtualization in its simplest form is the process of taking a
physical machine and subdividing it through software into the
equivalent of several discrete machines. While these machines
operate independently, they share the hardware resources of a
single server without impinging on each other. Computers of
many brands and stripes can be subdivided this way, begin-
ning with the IBM mainframe. IBM invented the concept of
virtualization. But virtualization has had its biggest impact on
x86 computers, the popular mass-produced models that use

Intel and AMD chips. These chips are found in everything
from lightweight netbooks to laptops, desktops, and powerful
data center servers. These computers typically run Windows,
Linux, Solaris for x86, or Netware as an operating system.
Virtualization boosts computers’ productivity at a time when
their capacities are being expanded rapidly. In effect, virtual-
ization has made servers built with PC-style parts the basis for

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