Virtual Architect

Understanding Cloud Scenarios

Sifting through the myriad of cloud offerings can be confusing, but not impossible. Here are five cloud services categories to keep an eye on.

We recently chatted with Dan Chu, VMware's vice president of emerging products and markets, about the company's approach to the cloud. From this conversation, we came to realize that cloud technologies are causing a lot of confusion. Almost everyone who offers an IT service now offers cloud services -- all of different variants -- and for an enterprise IT manager, distinguishing among them can be daunting. We've come up with five "cloud" service categorizations in the hopes of clarifying the topic and helping IT managers better understand potential cloud scenarios for their organizations.

Cloud Bursting: Bursting occurs when expanding an internal service, possibly running in a virtual machine (VM), to meet customer demand. You burst to the cloud by having additional VMs run the same service in a provider's infrastructure rather than in your own data center. This is what VMware and other hypervisor vendors tout as their cloud offerings. The VMs all run on the same hypervisor, which becomes the common denominator between your own and a service provider's data center. The hypervisor runs VMs of the same type without conversions in either environment.

Disaster Recovery (DR) Site: Lots of service providers offer DR services. In fact, many organizations choose to implement virtualization by first deploying the technology in a DR site. In this "poor man's" DR, you rely on a service provider's infrastructure to maintain internal services in DR mode. Within VMs the host can spin up quickly in the event of a disaster. Key to this strategy is the replication of internal data and systems to the cloud DR site.

Development and Test Environments: For many developers and testers, running tests and software trials in the cloud is now the only way to go. In fact, this is one of the cornerstones of Amazon's cloud offerings. Developers and testers can spin up a VM in the Amazon cloud in a few minutes, run their tests, gather the results and spin the whole thing down much easier than they can in their own environments. What's even better is that this whole process only costs pennies per session. You simply can't beat the pricing. The only reason you wouldn't use this service is if you have private data or code that you don't want to go out of your site.

Service Extensions: Lots of people already rely on the cloud to provide services they don't offer internally. For example, many small to midsize businesses that need Microsoft Exchange or Microsoft SharePoint services buy them from hosted providers so they don't have to build and manage the necessary infrastructure themselves. Obtaining professional-quality services such as a true Exchange 2007 mailbox or a SharePoint collaboration site -- rather than POP or IMAP mailboxes and generic Web services -- is worth its weight in gold. The services offer so much more functionality and, yet again, only cost a few dollars per month.

Infrastructure Extensions: When growth outpaces your ability to keep up with it, looking to cloud providers to extend your internal infrastructure is a good idea. You basically buy a chunk of the provider's infrastructure and manage it yourself just as you would internal systems. The only difference is that the extension isn't on your premises.

These five service categorizations show how you might introduce the cloud into the services you rely on to run the business. As you can see, virtualization isn't the only technology you'll use in the cloud, though it may well be part of your service provider's internal data center services. A lot of hype surrounds cloud technologies and services right now, but the cloud isn't necessarily new. In fact, you already may be using it in some form. The question is: Are you ready to increase your dependency on the cloud now that you have a grasp of the possible categorizations?

About the Author

Danielle Ruest and Nelson Ruest, both Microsoft MVPs, are IT professionals focused on technologies futures. They are authors of multiple books, including "Microsoft Windows Server 2008: The Complete Reference" (McGraw-Hill Osborne Media, 2008), which focuses on building virtual workloads with Microsoft's new OS.


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