Windows Architecture Best Practices

When dealing with a Windows Server Architecture, the Best Practice Recommendations suggest that each server role or application should be installed to its own individual server. There are a variety of reasons for this including:

1. Isolation of roles reduce the risk of conflict with each other. For example, registry and file system no longer conflict with other applications.
2. The loss of one server will not negatively impact processing of other servers. Additionally, depending on your architecture, you could bring down one server instance (image) for maintenance without impacting other application.
3. The complexity of applying patches is greatly reduced. Perhaps one of the greatest concerns when applying patches is trying to figure out the right combination of patches that are supported by all of the applications installed. With isolation, this complexity is removed because you only need to be concerned about patches that are unsupported by the application on the VM to be patched.
4. Lower complexity leads to a reduction in the chance for an outage. Now that everything is separated, there are less concerns about conflicts and incompatibilities. By reducing these concerns, or complexities, a greater uptime can be achieved.

The problem for Small Businesses

Without virtualization technology, physical servers are required to enforce role isolation. Not only that, additional licensing may be required for your specific operating system. Because of the limitation in funding that most small businesses have when it comes to I.T., role isolation has not been cost-effective, therefore most small businesses have simply consolidated their applications/services.

The solution

Moving to a virtualized environment allows for cost-effectively isolate servers by various roles. What about the additional licensing though? Well, Special virtualization licensing from software providers extends the value of each physical license. For example, with the release of Windows Server 2003 R2 in 2005, Microsoft updated the terms of its licensing agreements. Specifically, a company is entitled to install and license an additional four virtual instances for every purchased license of Windows Server 2003 R2 Enterprise Edition. For Windows Server 2003 R2 Datacenter Edition, an unlimited number of additional virtual instances can be installed and licensed.