Cloud services come in a variety of forms -- cloud bursting, disaster recovery support, outsourced services, development support, infrastructure extensions and more -- but private clouds fit in only one of these categories: virtual machine infrastructures.
That's because the private cloud exists for a single purpose: supporting the extension of your IT services when specific business needs arise or business conditions change. The best way to do that is to extend services through virtualization. Here's why:
- Scalability: The most common circumstance where an organization -- any organization -- needs a private cloud is when existing application infrastructures fail to meet demand. To meet demand, you must scale your application infrastructure -- the best way to do that is to extend through virtualization technologies. Virtual environments are easy to scale because they rely on shared hardware resources. In fact, the hypervisor -- or virtualization engine -- is the common denominator that helps support your private cloud (see Figure 1).
Figure 1. The hypervisor helps extend your IT infrastructure through virtual technologies.
- Security: Since they are stored within your premises, internal virtual infrastructures can be completely secured against outside interference. You don't need to open unnecessary ports in your firewalls, and you host your services in your own IT infrastructure.
- Flexibility: If you need extra power one day, fire up a new virtual machine. If you don't need it the next day, shut it down. This process can be completely automated through application performance monitoring tools.
- Green IT: Because virtual machines are designed to share hardware resources, they consume less power, space and cooling than a physical machine. Not only do they help you cut down on data center costs, but they also help you support "green" IT processes and reduce the impact on the environment.
- Dependability: Virtual infrastructures are proven technologies that have been tried and tested during the past decade In fact, because virtual environments always run on clustered host servers, they have better dependability than traditional physical implementations of your applications.
Cloud services are the next big thing in IT, and private clouds are the lion's share of this trend. That's why manufacturers such as Microsoft, VMware and Oracle are putting so much emphasis on the private cloud -- they want your business and if they get it, you'll be locked into their technology for the next few years because virtual machine formats from different manufacturers aren't compatible. They are interchangeable, and they can be converted to the Open Virtualization Format (OVF). But conversion requires time and is really only useful for virtual machine transport right now.
As you build your own private cloud, select a vendor that has a tried and tested virtualization technology. Also, make sure that this technology can dynamically expand and reduce your application services so your private cloud will not only be low-maintenance, but also support the changing business situations that nurtures the survival of your organization.
Danielle and Nelson Ruest are IT experts focused on virtualization, continuous service availability and infrastructure optimization. They have written multiple books, including Virtualization: A Beginner's Guide for McGraw-Hill Osborne, and MCTS Self-Paced Training Kit (Exam 70-652): Configuring Windows Server Virtualization with Hyper-V for Microsoft Press. Contact them at firstname.lastname@example.org or email@example.com.