Microsoft KB Archive/326239

= XADM: White Paper - Exchange 2000 Capacity Planning & Topology Calculator =

PSS ID Number: 326239

Article Last Modified on 6/13/2003

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The information in this article applies to:


 * Microsoft Exchange 2000 Server

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This article was previously published under Q326239



SUMMARY
Two fundamental questions many customers of Exchange 2000 Server are asking are:
 * How many &quot;users&quot; can be supported on a single Exchange 2000 server?
 * How many Exchange 2000 servers can be supported on a single Microsoft Windows 2000 Active Directory?

Because each deployment is unique, there are no simple answers to either of these questions.

With the release of Exchange 2000 Server, the Exchange Product Group at Microsoft is taking a different approach to server sizing and capacity planning than was historically used with Microsoft Exchange Server version 5.5 and earlier. With previous releases of Exchange, benchmark testing was the primary vehicle used for capacity planning. Benchmark testing often utilized &quot;canned&quot; user transaction profiles with names such as &quot;Light,&quot; &quot;Medium,&quot; and &quot;Heavy.&quot;

Scalability is not simply a factor of the number of users per server, but is strongly affected by the structure and pattern of the deployment. Before making an accurate prediction of the scalability of an Exchange deployment, one needs to also consider: the software client used to access mail, the associated server transactions with that client, the hardware used in the deployment, and the physical deployment itself.

The Exchange Product Group has invested in creating scalability testing tools that more closely mirror real world deployments. Many of these tools, along with documentation about how to effectively use them, can be found in the Microsoft Exchange 2000 Resource Kit. Two important tools that allow customers to probe the scalability limits of their systems are ESP and LoadSim.

Recognizing that the cost and time involved in testing the scalability of a deployment from the ground up is extremely high, the Exchange Product Group has also developed a resource utilization model that the customer can use to gain an initial foothold on the questions of scalability. The model was designed for flexibility, allowing the customer to ascertain an initial approximation of the scalability of their system even with the highly variable features seen in real deployments. Additionally, over the last few years as customers are increasingly relying on e-mail as a primary method for communication, and are making heavier use of their e-mail systems, the resource utilization model used in these benchmarks places higher demands on the server than previous benchmarks did in order to more closely mirror real world deployment scenarios.

This white paper details those variables that strongly affect scalability and how to use the resource utilization model developed by the Exchange team with these variables in mind.



MORE INFORMATION
The following file is available for download from the Microsoft Download Center:

Exchange 2000 Capacity Planning & Topology Calculator

For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:

119591 How to Obtain Microsoft Support Files from Online Services

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Keywords: kbinfo KB326239

Technology: kbExchange2000Search kbExchange2000Serv kbExchange2000ServSearch kbExchangeSearch

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