In our example, we started with six physical servers, and by virtualizing one domain controller, the Web server, the file server, and perhaps even the database server -- depending on load -- we reduced four physical servers to one. This leaves the Microsoft Exchange server still running on its own physical server. Not that Exchange servers have not been successfully virtualized, but the load on Exchange is often too much for a low-end virtualization installation.
Thus, we've reduced the total number of physical servers by half, while still providing the services required by the network. Also, by leveraging the snapshot features of the virtualization solutions, you can save time and effort by taking snapshots of the virtual machines before you apply service packs or application updates. If there's a problem with the update, you can quickly roll the server back to the snapshot and be back in business very quickly.
With the wide array of low-cost, high-powered servers and free virtualization solutions available today, there's very little reason not to add virtualization to the SMB toolbox. In fact, many businesses will find they can run their entire infrastructure with only two servers, using freely available virtualization frameworks. As with any IT endeavor, it will take time to adjust the solution to the needs of the business, but the benefits can be very significant -- especially when balanced against the low cost of entry.
Read more about virtualization in InfoWorld's Virtualization Channel.