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Virtualization has become a hot topic in recent years, but in reality, the
concept of virtualization is nothing new to information technology (IT). In
fact, whether or not anyone has been calling it virtualization, enterprise IT
has been using virtualization in everyday activities for decades.
Today enterprises are adopting specific virtualization technologies on the
promise of cost savings, but there are more strategic and long-term benefits
as well. Implemented at key points throughout the infrastructure, virtualization
can create flexible, responsive IT resources that enable organizations to better
align IT service with business needs.
Early virtualization
The core concepts of virtualization are deeply rooted within the IT architecture.
File servers are an example of basic virtualization, where data files (such
as spreadsheets, documents, etc.) are moved from individual desktop machines
onto transparent network devices. These files still appear to be hosted locally
via drive mappings while they are actually hosted on a network device. Application
load balancers are another example of virtualization that has existed in the
data center for years. They provide multiple services that appear to the user
as a singular operation. In both cases, the applications and data are decoupled
from the physical hardware connections so that services don't rely directly
on local, single-point-of-failure hardware.
How virtualization is being used today
Virtualization, regardless of the implementation, has one common architectural
goal: to disassociate access to a resource or service from the constraints of
its physical location and environment. In other words, virtualization breaks
the static bindings connecting a user, a service, a specific piece of hardware,
and a single location.
IT virtualization today can typically be categorized into two general types,
one-to-many and many-to-one. One-to-many virtualization allows one resource
-- a physical server for instance -- to be carved into many servers. Many-to-one
virtualization aggregates many resources -- such as disk drives -- into one
logical unit.
Server virtualization is the most prominent form of virtualization in the data
center today. IT organizations often use the term "virtualization"
to refer to server virtualization technology they are using to consolidate physical
servers in an effort to cut cost and increase flexibility. According to IDC,
server virtualization can reduce the number of physical servers required by
as much as 50 percent, reducing floor space, power, and cooling cost.
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