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VirtualizationChanged Everything

By Ken Hess

It is hard to think back on a time when I didn't have at least one virtual machine running somewhere. For me, it started in 1999, when I became a beta tester for a little startup company that had a single product we simply called, "VMware." VMware was cool because it allowed me to install a Windows 98SE "computer" on my Linux system. For fun, I also installed NT 4.0 and a Linux virtual machine on that same system. One day, I decided to turn them all on at once. To my surprise, they all had their own IP addresses and their own identities. I had a virtual network running on a single hunk of hardware and, to me, that was the definition of awesome.

These days that scenario sounds laughably trivial, but back then it was something very special. In fact, I looked at one of my employees and said, "Dude, this changes everything."

I wouldn't know how prophetic those words were for almost a decade.

In 2008, I went to VMworld in Las Vegas – the fifth VMworld. It was a huge celebration and a real opportunity to see how everything in computing had changed. I saw hundreds of companies whose sole purpose was to support virtualized computer technology. Some vendors sold management software. Other vendors sold virtualized desktop solutions. And, a few others sold virtual appliances. The entire show was a distinct departure from the tradeshows from a few years earlier, where vendors pushed branded hardware devices or new-fangled server hardware equipped with multiple processors, multiple gigabytes of RAM, and multiple disk configurations to power single operating systems and applications. Now, scenarios depicting a collection of hardware that hosts a single operating system border on the absurd – as absurd as my earlier assertion that virtualization changes everything.

Virtualization's absurdity reached new heights when CPU vendors eventually created processors that included virtualization extensions or what's known as "hardware-assisted" virtualization. These new CPUs made it possible to simplify virtualization software to the point that host software wouldn't install on hardware that didn't support virtualization. But, these days you'd be hard-pressed to find hardware that won't support virtualization. It's so ubiquitous that even my laptop can act as a VMware or Xen host.

I feel vindicated for gushing over a technology that, in 1999, some industry pundits labeled "cute" or "trendy." I felt the same way when my love of Linux and my predictions about its growth and adoption were also correct: Vindicated.

The reason why virtualization changed everything is that it meant the age of one operating system per computer was gone. It meant you could leverage that expensive hardware in such a way as to create very inexpensive services. It meant that virtual systems could be used for testing patches, new software, and new code without spending additional thousands of dollars on hardware for physical test systems. It also meant that Internet Service Providers (ISPs) could turn a better profit by offering virtual servers to their clients.

But, what has changed more than hardware and software is us. We changed our minds about virtualization and what it can do for computing: Cost savings through better utilized hardware, lower power requirements, lower cooling requirements, and less space consumed. We've changed our minds in favor of virtualization. We've come to refer to virtual machines as workloads and as virtual applications. We're now running almost every computing workload as a virtual machine: Databases, applications, services, and desktops.

Virtualization changed everything more than 40 years ago when it first emerged on mainframe computers. Mainframe admins thought in terms of workloads, applications, and services. The fun part of virtualization is that we discovered it all over again. And, we've built hardware to host it and software to manage it – all over again. We discuss resource pools, CPU allocation, memory allocation, and storage space as if it weren't made of individual computers at all. We've abstracted the underlying hardware into cycles, slices, and capacity as if we were using some computing machinery that only a few white-coat-donning technicians ever physically contact.

We hardly remember a time when we weren't running virtual machines.

Ken Hess * ADMIN Senior Editor