With the recent launch of HP Helion, and with HP Discover coming in a few weeks, it is a good time to talk about the difference between private cloud and virtualization.

Interestingly enough most companies assume that because they have virtualized 70-80% of their applications they have deployed a cloud environment.  This is the unfortunate result of marketing and sales people trying to move products or ideas without having an understanding of where we are headed, and what is happening in the market.  I confess I am guilty of this to some extent, I have written about private cloud being virtualizaiton, which is correct but incomplete.  So just what is the difference?  Well that largely depends on who you ask, but here is my take.

Application Centric

Virtualization came about to fill a gap in technology.  We were at a point where servers were more powerful than the applications, and so there was a great deal of wasted space.  When VMware started their server virtualization line, the big value was consolidation.  There was little to do with applications, it was about server consolidation, datacenter efficiency, and moving the status quo to the next level.  The application were only impacted in that they had to be supported in a virtual environment, but high availability, performance, everything was managed at the virtual server level similar to how it was managed at the physical server level previously.

In the cloud, abstraction is done at the application level rather than the server level.  the cloud rides on server virtualizaiton, but ideally applications should scale out, using multiple servers in a cluster each doing the same function with manager nodes to direct traffic.  While this may seem less efficient, since there needs to be multiple nodes to operate a single application, it actually frees the application from needing to reside in a specific datacenter or on a specific host, and indeed it should span multiple of each.  It also enables rapid scaling of applications since rather than adding additional physical CPU or Memory to the virtualized systems, you simply spin up additional resource nodes, and then when the peak demand is gone, you can tear them down.

So the first difference between virtualization and private cloud is the focus on applications rather than infrastructure. As we continue to explore this, I hope to tie this together and help to explain some of these differences.