Why virtualization is the foundation of cloud computing

I have always given credit to Microsoft Visio as the reason the term "cloud computing" came to represent services provided outside the data center. Whenever the network geeks want to draw out the details of their networks, they invariably use Microsoft Visio to create the pretty pictures using the pre-canned cloud graphics within Visio to depict the connections between locations.

Therefore, when talking about equipment outside the data center, they would always say "it's in the cloud".  They used the cloud metaphor to simplify the drawing of all the complex hardware and software components that made up the wide area network connections, or even their internal network connections in the data center. They hid the all the complexity by using a level of abstraction (the picture of a cloud) to represent the complex stuff within it. The metaphor stuck.

So when people refer to cloud computing, what they are really talking about is the ability to simplify IT by abstracting the complexity of the data center from a bunch of individually managed elements, into a service that is offered as part of a holistic "cloud". The metaphor is also true for cloud service providers, who offer IT services outside the data center.

Why is all this happening now? Virtualization.

Virtualization is the key to cloud computing, since it is the enabling technology allowing the creation of an intelligent abstraction layer which hides the complexity of underlying hardware or software.

Server virtualization enables different operating systems to share the same hardware and make it easy to move operating systems between different hardware, all while the applications are running.

Storage virtualization does the same thing for data. Storage virtualization creates the abstraction layer between the applications running on the servers, and the storage they use to store the data.

Virtualizing the storage and incorporating the intelligence for provisioning and protection at the virtualization layer enables companies to use any storage they want, and not be locked into any individual vendor. Storage virtualization makes storage a commodity. All this makes for some interesting ways for companies to reduce their costs.

As an example, let's say you're currently running an application on a brand-X server connected to Brand-Y storage at your primary location. You are conscientious, so you also bought a tape solution to back everything up to tape every night. Once the backup is completed, you call up your favorite local tape jockeys, and they pick all the tapes and drive them across town to their facility to protect them. In case of a fire, all your data is safe. everything is hunky dory. Right? Wrong!


  • Limited or no IT staff, or everyone is busy fighting fires.
  • Backup is taking too long, and is hammering the network.

    Need more tape drives.
  • Running out of space on the old storage array, but how do you migrate the data to a new array?
  • It takes way too long to call back a tape and recover a file.
  • Server outages for non-clustered physical servers.
  • No maintenance window.
  • Tons of tapes to manage.
  • Data security for everything on tape.
  • etc., etc., etc.

Now let's look at this with virtualization and cloud based data services in place:

You incorporate a storage virtualization solution between the brand-X server and brand-Y storage, and also implement server virtualization on top of the Brand-X server. You can now right click and mirror your data to any new storage array.

You can also load up the server with the applications now running on other servers, and get rid of all but one other server. You virtualize the other server, and can now move applications between them to do maintenance without downtime. You add tape virtualization, and can now add tape drives to your heart's content with the click of the mouse.

With all the virtualization complete, you can now call up a cloud service provider, and outsource backup and DR recovery to them for pennies on the dollar by replicating everything to their remote virtualized servers and storage at their location.


  • No tape media management, shipping, or storage costs.
  • No tape recall costs.
  • The cloud provider cuts tapes for you for long term archives.
  • No risk of losing data on tape.
  • No tape jockey vendor costs.
  • Everything is replicated offsite for rapid recovery and business continuance.
  • Server outages go away with VMotion.
  • Increased utilization of current hardware resources offsets future growth costs.

I have added all this up for quite a few companies, and what we always find is current costs drop across the board. Once people begin to feel more comfortable that their data is encrypted and secure from loss or prying eyes, many more companies will begin to virtualize their IT infrastructure, and begin outsourcing some of the functions or applications they currently provide internally. 

Christopher Poelker is the author of Storage Area Networks for Dummies, and he is currently the vice president of Enterprise Solutions at FalconStor Software.

Copyright © 2009 IDG Communications, Inc.

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