The Keys to a Robust Exchange Implementation

Test Your Plan
Now that you've given some thought to your Exchange deployment, you need to put your proposed design to the test. Microsoft offers a tool called the System Center Capacity Planner that's perfect for testing a potential deployment.

The tool lets you create a virtual model of the deployment. Not only can you model your Exchange organization's topology and server placement but you can also include such factors as proposed hardware for individual servers and network-link speeds. Then, you can run simulations against the model, taking into account such concerns as the number of users with mailboxes on each Exchange server, the types of activities that the users engage in, and the anticipated level of activity for each user. After completing the simulation, the System Center Capacity Planner shows you any areas in which your proposed design might not be able to reliably handle the anticipated workload.

Of course, you must remember that the simulation is based on simulated users and on simulated hardware rather than on real-world performance data. The simulation won’t be completely accurate because, in the real world, servers don’t always perform at anticipated levels, and users don’t typically conform to anticipated usage patterns. Therefore, to allow for a margin of error, I recommend adding 10 percent to the anticipated workload.

Obviously, the System Center Capacity Planner is a great tool for determining whether a proposed design will be adequate for your organization’s needs. The tool also lets you plan for the future. After you’ve tested your model, and you’re confident with what you’ve planned, you can play with various “What if?” scenarios. For example, you might want to see the effect of adding a hundred mailboxes to a particular server. If your network uses redundant WAN links, you can even see the effect of a link failure on network performance. The System Center Capacity Planner isn’t available for download from the Microsoft Web site, but it’s included with TechNet and MSDN subscriptions.

Fine Tune It
Even after you devote all this effort to planning your new Exchange deployment, you'll probably have to do some fine-tuning after the deployment is complete. You'll need to make sure that everything is performing as expected and that your configuration conforms to Microsoft's recommended best practices. Fortunately, Microsoft offers a free tool that's perfectly suited to this task: the Microsoft Exchange Best Practices Analyzer (ExBPA).

The ExBPA gathers configuration and performance data from various sources, such as the Windows registry, AD, Performance Monitor, and the metabase. After it collects this data, the ExBPA compares it with various best-practice rules. In doing so, the ExBPA can produce a report that details the steps you need to take to achieve better performance, stability, and security.

Maintain It
After you've fine-tuned your Exchange deployment, you'll turn your attention to its ongoing monitoring and maintenance, which is essential for several reasons. First, your Exchange organization will inevitably change over time. Even if you don't plan on adding servers or rearranging the deployment (although both scenarios are possible), the level of usage will change. Databases will grow, and you'll probably create additional mailboxes. The amount of spam that your Exchange implementation receives will likely fluctuate over time. All these factors will have some kind of effect on your Exchange organization's performance.

Second, regular maintenance is vital to ensuring ongoing reliability. A server's performance metrics and event logs often contain clues about situations that aren't yet problematic but that will become so if you don't act upon them. Keeping tabs on this type of information lets you correct various concerns before they can disrupt service.

Many organizations used to simply neglect the task of monitoring their Exchange servers. Performing comprehensive Exchange monitoring is a full-time job, and to properly interpret the data, the person in charge of reviewing the log and performance-metric data needs a high-level understanding of both Exchange and Windows, so many companies just crossed their fingers and hoped everything was OK. A few years ago, Microsoft Operations Manager (MOM) changed the scene by automating the task of server monitoring. MOM monitors both performance metrics and the event logs to gauge a server's health. MOM also proactively takes corrective measures in many situations, should the data point to a condition that could become problematic. It's worth noting that the System Center Capacity Planner is also designed to assist in a MOM server deployment.

Focus on the Key Areas
I can't overemphasize the importance of careful planning and testing in the quest for a robust Exchange deployment. I don't pretend to have the space here to address every aspect of growing a brilliant Exchange organization, but I hope I've shed light on the particular areas in which studious preparation will make the most difference to your organization's long-term stability.