10 Tips to Optimize Exchange 2003 Performance (Part 2)

Read the previous tips at 10 Tips to Optimize Exchange 2003 Performance (Part 1).

6.        Improve backup performance

Online backup is one of the most important operations to keep a healthy Exchange infrastructure. You’ll want to make sure that your daily backups have finished within the time frame available, so that you can use them in case of a disaster, or just to recover some mailboxes.

Currently there are many backup solutions available from different vendors, but you have one that is 100% supported and for free: Windows Backup aka NTBackup. Unfortunately NTBackup doesn’t come pre configured for performance, so there are a couple of things you can do to improve it.

I already wrote an article dedicated to this issue, Improve your Exchange Backup (http://www.msd2d.com/newsletter_tip.aspx?section=exchange&id=cb6e0238-9a1f-4dc1-85a9-1e69a8abfaad), so I’ll just post the necessary tweaks:

Modify specific registry values that optimize the data throughput of the built-in backup engine. These entries are located under the key HKEY_CURRENT_USER\Software\Microsoft\Ntbackup\BackupEngine\ (if you don’t see the BackupEngine subkey you’ll have to run Windows Backup at least once):

Logical Disk Buffer Size = 64

Max Buffer Size = 1024

Max Num Tape Buffers = 16

These settings will boost data throughput from 640MB/min to 1200MB/min.

Obtain a new version of NTBackup (http://support.microsoft.com/?kbid=839272). The revised version of NTBackup, which will be included on Windows Server 2003 Service Pack 1, provides a new command-prompt switch, /FU. This switch enables a “file unbuffered” setting to bypass the cache manager and thus resolving a cache contention issue. This change provides a number of benefits during the disk-to-disk backup process:

  • Sustainable throughput over time (remember the 1200 MB/min data throughput? Without the revised version that throughput will suffer some degradation)
  • Reduction in processor utilization (peak utilization reduced to 30 percent on average)
  • Elimination of impacts to the system process during the backup job

7.        Install and use Exchange Best Practices Analyzer (ExBPA) Tool

The ExBPA Tool, available as a free download, is one of those pieces of software that no administrator can live without. The Microsoft Exchange Team has really done a great job. Most of the tips I’m writing in this article are probably referenced in that tool.

The tool helps you to proactively identify configuration problems and by that, keeping your Exchange Server messaging infrastructure running smoothly. You can quickly get a report with critical configuration issues, potential problems, and non-default product settings, by collecting and analyzing data from each server in the topology.

So, the advice here is to run a Health Check with ExBPA, carefully read all the issues and critical errors listed and take the proper actions to correct them. By implementing the recommendations made by the tool, you can expect to achieve an overall improvement to your experience with Exchange Server, achieve greater performance, scalability, reliability, and uptime.

As Microsoft states, it has State-of-the-Art Expert System Analysis and you should demand nothing less than State-of-the-Art for your messaging system.

8.        Use Outlook 2003

Outlook 2003 has some great new features, most of them were designed to work together with Exchange Server 2003. When you combine the power of these two products you get an instant performance increase.

Cached mode, traffic compression and incremental synchronization are just some of the features that will contribute to the effective use of your resources.

The Microsoft Exchange Team has done some thorough measures of the traffic generated by different Outlook versions and they concluded that Outlook 2003 is the most efficient of the clients, mainly due to compression. They’ve compiled the results on the document “Client Network Traffic with Microsoft Exchange Server 2003”, available for download at http://www.microsoft.com/technet/prodtechnol/exchange/2003/clinettraf.mspx.

If you want to prevent previous versions of Outlook from connecting to your Exchange servers, all you have to do is some registry modification. There are detailed instructions in the KB article “XADM: Feature to Disable MAPI Client Access”, http://support.microsoft.com/?kbid=288894.


Outlook 2003

Outlook XP

Outlook 2000

Outlook 97

Cached Exchange mode


Intelligent Connectivity


RPC Connectivity to Exchange via HTTP


Synchronization groups





Background synchronization of local and server folders



Differential, offline address-book synchronization with server



Incremental change synchronization


Smart change synchronization


Pre-synchronization reporting


Offline synchronization





Buffer packing


MAPI compression


Skip bad items


Outlook performance monitoring


Unicode PST Support



Cancel request to server



Send and Receive groups


LDAP support and default list



Table 1: Outlook feature comparison

9.       Ensure that online maintenance runs

Online Database Maintenance helps keeping mailbox and public stores in good health. It does that by performing three major tasks:

  • Checks Active Directory for any deleted mailboxes.
  • Permanently deletes messages and mailboxes older than the configured retention period.
  • Performs online database defragmentation.

By eliminating objects and rearranging them you get a much more efficient database, with data stored optimally, reducing disk I/O.

By default, online database maintenance is scheduled to run between 01:00 and 05:00. As this is a very disk-intensive task and affects the server where the online maintenance is being run, it should be run during non-business hours when the server can better handle the additional load.

You must ensure your online backups don’t conflict with your scheduled maintenance interval for any databases in the same storage group. If they overlap, backup will stop the online defragmenting part of the scheduled maintenance and the database may not be able to finish defragmenting.

So, the advice here is to ensure coordination between online maintenance with the online backup strategy. Make sure you have at least a 15 minutes gap between start times and never disable online maintenance.

If you want to know more about IS Maintenance, there’s a great post on JeremyK’s Blog: http://blogs.msdn.com/jeremyk/archive/2004/06/12/154283.aspx.

Figure 2: Online maintenance interval

10.        Use antivirus and antispam

I think this one turns out to be quite obvious. Besides avoiding virus effects, you’ll have to handle fewer messages, as unwanted ones are barred outside your messaging system.

Ensure that adequate antivirus software is installed on all your servers. Keep the software up-to-date with the latest virus signature files. If possible, use the automatic update feature of your antivirus application.

Don’t forget that special care must be taken if you’re using file-level antivirus. If you want to use a file-level scanner, you should exclude Exchange directories from the scan. There’s a Microsoft Knowledge Base article with further guidelines, “XADM: Exchange and Antivirus Software”, (http://support.microsoft.com/?kbid=328841).

There is some tuning you can do regarding your AV engine. Here, your best approach is to use the Exchange Best Practices Analyzer Tool (ExBPA). ExBPA will advise you with the optimum configuration for your server.

For antispam you may consider using Microsoft Intelligent Message Filter (IMF) or any other product commercially available. You should use antispam at the edge of your organization. Depending on your email volume, you may want to consider using a dedicated server for this purpose, as spam identification can be resource intensive.


Performance is a very passionate subject. There are so many things to say about improving a system’s performance and stability. I decided to write just 10 tips, but I could find 100 more to talk about. I tried to choose the most effective settings that will give you the best results and, besides that, 10 is a nice round number.

And remember, use performance tools before going live, in order to validate that the server can handle the predicted load. There are at least two tools you should run: Jetstress and Load Simulator 2003 (Loadsim). Jetstress and Loadsim are available to download at the Microsoft site (http://www.microsoft.com/exchange/downloads/2003/default.mspx). Also keep in mind that performance tools in general should only be used in a test environment. If possible, format and reinstall the servers after all the necessary measures are taken.

I would like to end this article going back to tip #1, documentation. You can find much information regarding performance and tuning, so I’ll mention some links I think are quite nice:

Exchange Server 2003 Performance and Scalability Guide

Troubleshooting Exchange Server 2003 Performance

Exchange Server 2003 Tips and Tricks

Read the previous tips at 10 Tips to Optimize Exchange 2003 Performance (Part 1).

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