In the physical world, a SharePoint deployment, for example, might utilize two or more front-end servers, a database server, an index server, and an application server. Although role-based deployments tend to improve security and efficiency, they also tend to drive up software licensing and hardware costs. Further, individual servers tend to be underutilized. A front-end Web server for instance, probably won't use much of the server's hardware resources.
With virtualization, a SharePoint architect can place multiple SharePoint roles onto a single physical server while isolating each individual role within its own virtual machine. In doing so, an architect can decrease hardware costs by using existing hardware. He may also thus reduce the licensing costs associated with the Windows operating system (depending on which virtualization product is used).
But while there are many benefits of virtualizing SharePoint 2007 some aspects of the virtualization process can cause problems. The most obvious relates to overloading the host server. Some administrators have gotten out of the habit of performing capacity planning prior to doing a server deployment, because physical servers are typically equipped with more resources than are required for many common applications. In a virtual environment, though, guest machines are competing for a finite pool of resources, so capacity planning becomes critical.
Another critical issue is guest machine placement. In small organizations, for example, it may be tempting to place all of the organization's virtual SharePoint servers onto a single host. The problem with this approach is that the host represents a single point of failure. In this configuration, if a host server fails, every virtual machine on it also fails.
A better approach is to distribute your SharePoint servers to eliminate a single point of failure. If your organization uses multiple front-end Web servers, for example, you should distribute those front-end Web servers among multiple hosts. There is no benefit to placing multiple SharePoint front ends on a single host server.
Finally, refrain from making snapshots of your virtual SharePoint servers. Microsoft does not support the use of virtual machine snapshots in conjunction with individual SharePoint servers. Restoring a snapshot may cause the server to create issues within the rest of the farm.
Virtualizing SharePoint can reduce hardware costs and help use your existing hardware more efficiently. But even with these benefits, it is important to take the time to thoroughly plan your virtualized SharePoint deployment to avoid common -- and critical -- mistakes.
About the author: Brien M. Posey, MCSE, is a five-time recipient of Microsoft's Most Valuable Professional (MVP) award for his work with Exchange Server, Windows Server, Internet Information Services (IIS), and File Systems and Storage. Brien has served as CIO for a nationwide chain of hospitals and was once responsible for the Department of Information Management at Fort Knox. As a freelance technical writer, Posey has written for Microsoft, TechTarget, CNET, ZDNet, MSD2D, Relevant Technologies and other technology companies. You can visit his website at www.brienposey.com.
This was first published in February 2010