Integrating virtualization into the operating system is a bad idea. You're probably wondering why bundling more features into an OS isn't a good idea.

There are many reasons why bolting on a hypervisor to an OS is a bad idea.

First, it requires you to upgrade to the latest operating system version, such as the upcoming Linux OSes (Red Hat 5, SLES 10) to get virtualization capabilities. How long did your last operating system upgrade take? It also means that you have yet another operating system to manage per server. Who is going to pay for the additional calories and the redirection of scarce system administrator focus from more strategic activities that advance the business to patch management and other administrative tasks for these new operating system instances?

The operating system vendors are taking a very parochial view towards their support matrix. As in, "We'll support our latest operating system version, and maybe one version prior." What if you want to run Windows and Linux side by side? Silly you say? Not for disaster recovery scenarios... there you'll need every ounce of hardware and then some to keep your systems running.

Operating system vendors like to add features and force their customers to upgrade to the latest versions. This is exactly the wrong approach for virtualization. Virtualization solutions should provide the absolute necessary capabilities in the virtualization stack and put anything that is not related to running operating systems efficiently outside the OS, in an external to the OS management system. This allows capabilities such as workload management and business continuity to work across operating systems and physical resources.

It's no surprise that the OS vendors are jumping into the virtualization space. Before jumping in with them, ask how much effort it's going to take, and whether it meets the reasons you're deploying virtualization. We commonly see companies start with server consolidation, then rapidly move to deploying virtual servers from "golden images", followed by business continuity and ultimately policy-based automation and dynamic workload management. Outside of trying to consolidate new OS installations (an oxymoron -- how can you possibly consolidate new OS installations?), it's not clear what value the OS vendors can provide to users' virtualization goals.