Topic Last Modified: 2006-02-21

The Microsoft® Exchange Server Analyzer Tool queries the Active Directory® directory service to determine the value of the msExchESEParamCacheSizeMax attribute for all mailbox store objects. If the Exchange Server Analyzer finds the value of the msExchESEParamCacheSizeMax attribute for any mailbox store to be more than 0 but less than 219727, a non-default configuration message is displayed.

In Exchange 2000 Server, a large area of the virtual memory used by STORE.EXE is allocated for the ESE buffer. Exchange 2000 Server uses a hard-coded default of 858 megabytes (MB) for this buffer. In Exchange Server 2003, ESE buffer allocation is based on the presence of the /3GB switch in the Boot.ini file. If the /3GB switch is present, the ESE buffer is tuned to 896 MB. If /3GB is not present, the ESE buffer is tuned to 576 MB. While auto-tuning is useful in every case, you may want to override the auto-tuning and manually set a value more appropriate for your environment. While you can tune this value to any multiple of 8192, it is recommended that you only use a value from the following table.

Recommended Value Memory Allocated Comments


576 MB

This is the recommended minimum. Do not set the value any lower. This value is useful on virtual memory-constrained servers, and on Exchange Server 2003 computers that run on Microsoft Windows® 2000 Server, which does not support the /3GB switch. This is also the default value on systems that do not use the /3GB switch.


768 MB

This value is recommended on servers with large amounts of virtual memory that log event 9582 frequently.


858 MB

This is the default value in Exchange 2000 Server, and it is a good value to use on systems you are upgrading in-place that have large amounts of virtual memory.


896 MB

This is the default value in Exchange Server 2003, and a good value to use on new systems unless your Application event log indicates otherwise with the presence of 9582 events.


1.2 GB

This is the maximum value that you can set. This value should only be used on systems with 2 GB or more of physical memory.

Before you reconfigure this value, you should monitor the amount of virtual memory consumed by the STORE.EXE process. You can do this by monitoring the Process performance object in Windows. On systems with the /3GB switch, the Virtual Bytes counter for the STORE.EXE instance of the Process object should be less than 2.8 GB. On systems without the /3GB switch, it should be less than 1.8 GB. If the values are greater than these amounts, you may need to decrease the value for msExchESEParamCacheSizeMax. If the values are lower than this, you may need to increase the value for msExchESEParamCacheSizeMax.

If you incorrectly modify the attributes of Active Directory objects when you use Active Directory Service Interfaces (ADSI) Edit, the LDP (ldp.exe) tool, or another Lightweight Directory Access Protocol (LDAP) version 3 client, you may cause serious problems. These problems may require that you reinstall Microsoft Windows Server™ 2003, Exchange Server 2003, or both. Modify Active Directory object attributes at your own risk.

To tune the msExchESEParamCacheSizeMax attribute

  1. Open an Active Directory editor, such as ADSI Edit.

  2. Double-click the Configuration container.

  3. Expand CN=Services.

  4. Expand CN=Microsoft Exchange.

  5. Expand CN=<Exchange Organization Name>.

  6. Expand CN=Administrative Groups.

  7. Expand CN=<Administrative Group Name>.

  8. Expand CN=Servers.

  9. Expand CN=<Exchange Server Name>.

  10. Right-click CN=InformationStore, and then click Properties.

  11. In the attributes field, scroll to and then double-click msExchESEParamCacheSizeMax.

  12. In the Value field, type the value that you want to set. Use the table in this article to determine the optimal value for your system. Note that the value that you use must be a multiple of 8192.

  13. Click OK, and then click OK again.

  14. Close the Active Directory editor, and then restart the Microsoft Exchange Information Store service for the change to take effect.

For more information about optimizing memory usage, see the Microsoft Knowledge Base article 815372, "How to optimize memory usage in Exchange Server 2003" (

For more information about the msExchESEParamCacheSizeMax attribute, see the Knowledge Base article 266768, "XSTR: How to modify the Store Database maximum cache size" (