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

servers, applications, and data from specific physical assets. Storage virtual-
ization takes those same benefits and extends them to the underlying storage
domain. Just as using networked storage for virtual machines instead of DAS
means that there is no single point of failure at a disk system level that can
bring down many virtual machines at once, storage virtualization adds yet
another layer of protection against failures—extending full hardware inde-
pendence from the server domain to the storage domain.

Chapter Summary and Conclusions

The following conclusions are from this chapter’s discussion on virtualiza-
tion and green IT:

■ Virtualization is the most-promising technology to address both the
issues of IT resource utilization and facilities space, power, and cooling
utilization.
■ Many IT companies address the situation from end to end—at the server
end through power management features, and at the data center ends ptg
through integrated IT/facilities’ modular solutions.
■ IT virtualization includes server virtualization, storage virtualization,
client virtualization, virtualization using cluster architecture, and virtual-
ization of blade servers.
■ The ultimate objective and benefit of virtualization is the significant IT
flexibility it brings corporate users. IT virtualization can benefit data
protection, business continuity, and disaster recovery.