Compaq ProLiant 6000 Performance of Microsoft Exchange Server 5.0 on Compaq Pr - Page 19

WHITE PAPER (cont.) NOTE: Testing by both Microsoft and Compaq has shown that client/server RPC traffic is not an area of great concern. In our simulations, even loads as high as 3000 users showed a network utilization of approximately 15% for 10Base-T (10 megabit) and approximately 2% for 100BaseTX (100 megabit). ECG052.0897 1...9 Network Subsystem The network subsystem in many respects is a non-issue in Exchange Server performance. Every indication is that, while network infrastructure should be an important consideration for Exchange Server planning and deployment, network bandwidth is not an area of resource contention with Exchange Server. Exceptions to the above are in two areas. The first concerns the support of users over WANs and remote sites via slow links. Careful analysis and planning should be done when deploying Exchange Server to user populations over wide-area or slow links. Previous recommendations regarding proper workload characterization and analysis are applicable. The area covered by this exception is outside the scope of this paper, but several resources are available on the subject from Microsoft Product Support Services (PSS) and Microsoft Consulting Services (MCS). The other exception involves Exchange Server remote procedure call (RPC) traffic. The fundamental communication mechanism in Exchange Server is the RPC. Both Exchange servers and Exchange clients use RPCs to communicate. Of concern for capacity planning purposes is inter-server RPC traffic. Exchange servers use RPCs to conduct such activities as DS replication, PF replication, and mail transfer. In the design of Exchange Server sites, careful analysis should be carried out to plan for RPC traffic between servers. For example, a dedicated backbone between servers is one option for ensuring adequate bandwidth for inter-server RPC traffic. Once again, Microsoft has dedicated substantial research and testing to these issues in order to assist customers in addressing them. Conclusions and Recommendations The purpose of this section is to provide general guidelines for configuring an Exchange Server computer. You should read it and apply the data in this paper to your own configuration decisions. It is organized into four categories: processor subsystem, disk subsystem, memory, and general. Processor • Typically, the processor subsystem is not the key resource bottleneck in Exchange Server 5.0. However, if the server will be supporting many users, and especially if the server will be handling many different non-IS processes such as Public Folders, Free/Busy, DL Expansion and DS Replication, multiple CPUs will be a benefit. • The Pentium Pro has clear advantages over Pentium-based systems running Exchange Server. Pentium-based servers are not recommended for user loads greater than 1000. Disk • Place the database logs on a separate physical volume from that occupied by the Information Service databases. Using the two ports of a SMART-2 controller for this works well, as the SMART-2/P and SMART-2DH can perform simultaneous I/O on both ports. • The database store (IS) volume should be composed of an array of at least three disks, and it should be fault tolerant. Due to the random nature of this volume's I/O, RAID 5 is a good fault tolerance configuration. Although RAID 5 imposes a performance penalty for disk WRITEs, the ratio of disk READs to disk WRITEs is about 3:1. This ratio can change if you have a very large IS buffer, but it generally holds true.