New Things to Virtualize
Virtualization is like a Sears 144-piece toolset -- there's something for every job.
Most in IT only pull out the most popular tool, server virtualization. And there's nothing wrong with that. You can load multiple virtual servers on one physical server, making the server more efficient. And it saves on physical hardware and associated costs like cooling, cabling and precious floor space. But that's like only using the hammer and ignoring the other 143 tools. Instead, let's Take 5 other tools out for a spin.
Take 1 Storage Virtualization.
It's hard to do server virtualization and disaster recovery without storage virtualization. Seeing your storage-area network (SAN) as a logical -- rather than physical -- entity allows you to make storage mobile, one of the chief benefits of virtualization.
An important related technology is "thin provisioning," which means assigning storage to a resource on an as-needed basis, rather than setting aside a ton of acreage that may never get used.
Take 2 PC Virtualization.
I work on a Mac (but I'm not a glassy-eyed zealot, so no flamethrowers, please). I love it, but there are some things for which I need a PC. Rather than buy another machine, I just fire up VMware Fusion, which loads Windows Vista into a virtual machine (VM) and ... voilà! Bill Gates, meet Steve Jobs. It works the same way on PCs, with virtual PC products from the likes of Microsoft, VMware and Parallels. This, by the way, is not desktop virtualization, which is described next. If that confuses you, welcome to the human race. Most folks don't grasp the difference.
Take 3 Desktop Virtualization.
Taking further the Citrix model of remote application delivery, desktop virtualization provides the end user the entire desktop -- the OS along with the apps -- in one virtualized package. Because the package resides on the server, it centralizes and significantly eases desktop management, plus it provides better security. And it ain't PC virtualization -- I hope you're catching on now.
Take 4 Application Virtualization.
This one is also often confused with the previous two, PC virtualization and desktop virtualization. Application virtualization separates a program from the underlying OS by doing cool stuff like writing to a virtual Registry. This means you can take it anywhere and load it onto almost any computer. It also won't crash your system, because it doesn't deal directly with the hardware. Keep an eye on this usage of virtualization: VMware thinks it's important enough that it just bought a leading app virtualization company, Thinstall.
Take 5 I/O Virtualization.
While virtualization is great at centralizing management, it can also introduce new complexity, making the back of a server look like the back of Medusa's head. Consider a server running VMware ESX Server. According to one study, 75 percent of VM servers have seven or more I/O cables per server; most are for networking and storage purposes. It's possible in these cases for I/O to become the performance bottleneck. I/O virtualization abstracts and manages these I/O connections, cutting down drastically on the need for cabling and switches, leading to a leaner, faster virtual infrastructure.
What tools are you using? Let me know at firstname.lastname@example.org.
Keith Ward is the editor in chief of Virtualization Review.