Public vs. Private Cloud
No one can argue that cloud computing is on the rise. But exactly how these Internet-based IT services are going to storm the enterprise market – as public clouds shared by all or as private clouds operated by organizations to serve their own employees – is up for debate.
Cloud computing refers to IT services that are purchased and delivered on demand over a network, either the public Internet or a private IP-based network. Cloud computing services are powered by highly virtualized processing and storage systems in data centers that are made available via a Web interface to remote users.
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Cloud computing offers CIOs several advantages – including faster set-up, easier scalability and no capital expenditures for hardware and software – but it also has security risks, performance trade-offs and inherent networking costs.
Whether they realize it or not, more CIOs are relying on cloud computing, which can also be called utility computing, grid computing or software as a service. Nearly 60% of European CIOs reported using specific cloud computing services although many didn't understand that fact.
Cloud computing is poised for significant growth over the next few years. Gartner, for example, projected in March 2009 that sales of cloud computing services would almost triple over five years, from $56 billion in revenues in 2009 to $150 billion in revenues in 2013.
Much of the growth is coming from cloud-based applications such as Google Apps and Zoho, which run on the public Internet and are open to any user that pays with a credit card. These Web-based applications are gaining popularity in such areas as salesforce automation, customer service, accounting and expense management.
Another burgeoning area is cloud-based computing platforms such as Amazon's Elastic Computer Cloud (EC2). These services allow users to rent virtual computers for developing or running their applications and to pay for them on an hourly basis. Users can purchase cloud-based data storage services, too, from Google, Amazon and others.
Private clouds, on the other hand, are owned and managed by an organization and restricted to particular users, who can provision their own services. Some vendors, including Amazon with its Virtual Private Cloud offering and Microsoft, are pushing private clouds as the more likely option in the enterprise market.
One proponent of private clouds is the Defense Information Systems Agency (DISA), which claims to run a safer, more reliable cloud-computing platform than Google's. DISA's Rapid Access Computing Environment offers processing power and applications to military users for a monthly fee. Users can provision their own services in as little as 24 hours via a Web portal.
Private cloud services are expected to be popular across the U.S. federal government, not just in the Defense Department. Federal CIO Vivek Kundra is encouraging agencies to embrace private cloud computing services as a way of saving taxpayer dollars and improving IT services.
Read more about data center in Network World's Data Center section.