After fine-tuning your Exchange Server architecture design model, you can use System Center Capacity Planner's...
built-in Hardware Editor to adjust your model so that it more closely resembles your network's actual configuration.
Accessing and using the Hardware Editor
To access the Hardware Editor, launch the Capacity Planner application and select
Edit Computer Configuration with the Hardware Editor.
When you created your architecture model, you specified hardware for up to three different types of servers. You also were given the opportunity to select various types of hard disks. However, it's somewhat unrealistic to assume that the wizard will be able to create a model that accurately reflects your network's hardware configuration.
Unless you're going to build the model network from the ground up, you probably have a variety of hardware in place, rather than just having a couple of different types of servers. The wizard also only gives you a limited number of choices regarding server hardware. There is a good chance that you are using hardware that isn't on the list; therefore, you must choose hardware that is similar to what you have.
The Model Wizard is useful in creating a model that is somewhat similar to your network. The Hardware Wizard lets you fine-tune that model to accurately reflect the server hardware that you're using.
If you wanted to change an object within the model, such as a site link or a usage profile, you could double click on the object that you want to modify to expose its attributes. But the Hardware Editor works differently.
When you add a piece of hardware using the Hardware Editor, you're not changing the model. Instead, you're adding an item to a list of available hardware choices. For example, the Hardware Editor contains a list of about 12 different hardware configurations. You can use the Hardware Editor to add your own configuration to the list. This configuration will then become available through the Model Editor.
The Hardware Editor is divided into two sections:
- The Device Configuration section lets you create or modify listings for individual devices, such as CPUs, hard disks and disk arrays.
- The Computer Configurations section lets you define a computer as a collection of various devices.
Figure 13 gives an example of how the Hardware Editor works. I selected the Device Configuration section and CPU as the device type. I then clicked on New Device, which lets me edit and specify CPU attributes, such as manufacturer, speed, number of processors, number of cores, cache sizes and bus speed. Choosing a single disk or a disk array as the device type, rather than a CPU, would produce a similar screen with options appropriate to the device type selected.
Figure 13. The Device Configuration portion of the Hardware Editor lets you add custom hardware configurations.
After you define components, you can define a computer based either on the predefined components, custom components or a combination of the two. To do so:
- Select the Computer Configurations option and click on New Computer. You will see a screen similar to the one in Figure 14. The section at the bottom contains a list of components.
Figure 14. The Computer Configurations section of the Hardware Editor lets you define a computer based on the components listed in the Device Configuration section.
- To define a computer, select a CPU and click Add Device. You must repeat the process to add either a disk or disk array. Keep in mind: the editor allows you to add multiple disks or disk arrays to a computer. After defining any necessary computers, you can now work them into your model.
- Go to the Model Editor and drill down into a site until you've exposed its individual servers.
- Right click on a server and select the Edit Server Hardware Configuration option from the menu. You will then see a screen similar to the one shown in Figure 15.
Figure 15. The Model Editor lets you specify the exact hardware configuration for each server in your Exchange organization.
If you look at the editor at the bottom of the screen, you will notice that the first option is the server name. By default, the Model Editor fills in a generic name -- Server 3, for example. Replace this generic name with the real name of the server that you are simulating. This will help clarify your simulation results.
The Configuration Details section of the editor shows the server's current configuration. However, you can use the Apply New Configuration dropdown list to select any computer defined within the Hardware Editor. This allows you to simulate hardware for each individual server in your Exchange organization fairly accurately.
Because System Center Capacity Planner doesn't take into account the server's memory, the simulation is not 100% accurate. The Capacity Planner assumes that the server has adequate memory installed; therefore, if one server is low on memory, it might not perform as well as the Capacity Planner tool indicates.
Another factor that could potentially prevent Capacity Planner from accurately simulating your server's performance is that it assumes that the hardware is dedicated to run Exchange Server. If the server is running other applications or services, those processes will consume server resources and diminish server performance to some extent.Running a network model simulation
At this point, your model should be an accurate representation of your actual network. To check:
- Choose the Model Summary option from the column on the left. This will provide you with a detailed breakdown of the way that you've configured the various objects within your model. If everything appears to be correct, it's time to run the simulation.
- Click Run Simulation on System Center Capacity Planner's task bar.
The amount of time that the simulation will take to complete depends your model's complexity. I created a model with a central site, four branch sites, dozens of servers and thousands of users. I ran the simulation against the model on a 3.2-GHz Pentium 4 with 2 GB of RAM, and the simulation took just under one and a half minutes to complete.
- When the simulation finishes, go to Global Topology to view the results. As shown in Figure 16, Capacity Planner explains that my Internet link is overloaded. Double clicking on the error displays a help window containing a few reasons why I might have received this message.
Figure 16. The Capacity Planner gives you an error messages when a portion of the Exchange organization cannot handle the anticipated workload.
Capacity Planner allows you to look at "what-if" scenarios. For example, the simulation alerted me that my Internet connection was too slow. I could tweak my model and rerun the simulation to see if doubling my connection speed would solve this problem.
System Center Capacity Planner can also test the effects of future growth. For example, if you were asked if adding another 150 users to your Exchange Server organization would cause any problems, you could use the Capacity Planner to find the answer.
This tool could build a model of your existing Exchange Server organization and test the effects of adding users. Doing so would tell you if your Exchange organization was up to the task; it also would show you what problems could occur if your current deployment isn't adequate. You could then use these simulation results to justify additional hardware purchases.
HOW TO DESIGN AN EXCHANGE SERVER ARCHITECTURE MODEL
Step 1: Design an Exchange Server architecture model
Step 2: Fine-tune your Exchange Server architecture design model
Step 3: Customize your Exchange Server hardware configurations
|ABOUT THE AUTHOR:|
| Brien M. Posey, MCSE
Brien M. Posey, MCSE, is a Microsoft Most Valuable Professional for his work with Exchange Server, and has previously received Microsoft's MVP award for Windows Server and Internet Information Server (IIS). 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, Brien has written for Microsoft, TechTarget, CNET, ZDNet, MSD2D, Relevant Technologies and other technology companies. You can visit Brien's personal Web site at http://www.brienposey.com.
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