How to Set the msExchESEParamLogBuffers Attribute for Exchange
The msExchESEParamLogBuffers storage group attribute governs the number of Extensible Storage Engine (ESE) log buffers that are used by the Exchange information store. ESE uses a set of log buffers to hold information in RAM before it writes to the transaction logs. Using these buffers improves transaction logging performance. For large servers, the default value of 84 is too low. This can cause excessive disk I/O operations to the transaction log drive and, therefore, significant decrease in performance if the server is under load or if users are sending large messages. Increasing the number of ESE Log Buffers improves performance, although it also causes more virtual memory usage.
To correctly set this value, use the following information:
For Exchange 2000 Server, Exchange 2000 Server Service Pack 1 (SP1), or Exchange 2000 Server Service Pack 2 (SP2), set this value to 9000.
For Exchange 2000 Server Service Pack 3 (SP3), set this value to 512.
For Exchange Server 2003, a default value of 500 is used, and you should change the value for the msExchESEParamLogBuffers attribute to 9000.
Note
If you previously tuned log buffers to 9000, make sure that you manually reduce this setting after you apply Exchange 2000 Server SP3. This change is not made automatically when you install Exchange 2000 Server SP3.
If you have log stalls, this may be caused by too low a buffer and you can raise this value to 9000. The Database\Log Record Stalls/sec performance counter can be monitored to determine whether log stalls are occurring. Do not use a value greater than 9000, as that can corrupt transaction log files.
Note
Log Record Stalls/sec is the number of log records that cannot be added to the log buffers per second because they are full. If this counter is non-zero most of the time, the log buffer size may be a bottleneck.
You can configure the value for the msExchESEParamLogBuffers attribute using a tool such as the Active Directory Service Interfaces (ADSI) Edit snap-in, the LDP tool, or any other LDAP version 3 client.
Warning
If you use the ADSI Edit snap-in, the LDP tool, or any other LDAP version 3 client, and you incorrectly modify the attributes of Active Directory objects, you can cause serious problems. These problems may require that you reinstall Microsoft® Windows Server™ 2003, Microsoft Exchange Server 2003, or both. Microsoft cannot guarantee that problems that occur if you incorrectly modify Active Directory object attributes can be solved. Modify these attributes at your own risk.
Procedure
To configure the msExchESEParamLogBuffers attribute for Exchange
Start ADSI Edit.
Double-click the Configuration container, expand CN=Services, expand CN=Microsoft Exchange, and then expand CN=<ExchangeOrganizationName>.
Expand CN=Administrative Groups, expand CN=<AdministrativeGroupName>, and then expand CN=Servers.
Expand CN=<ServerName>, expand CN=InformationStore, right-click CN=<StorageGroupName>, and then click Properties.
In the Attribute Editor, click the msExchESEParamLogBuffers attribute, and then click Edit.
In the Edit Attribute box, set the value to 512 for Exchange 2000 Server or 9000 (for example, clear the value) for Exchange Server 2003.
Click Apply, and then click OK.
Close ADSI Edit and then restart the Microsoft Exchange Information Store service for the change to take effect.
For More Information
For detailed information about the msExchESEParamLogBuffers Storage Group Attribute, see the Exchange Server Team Blog article, You Had Me At EHLO: msExchESEParamLogBuffers Storage Group Attribute at https://go.microsoft.com/fwlink/?linkid=64793.
Note
The content of each blog and its URL are subject to change without notice.
For more information about ESE log buffers, see Microsoft Knowledge Base article 328466, XADM: ESE Log Buffers That Are Set Too Low Can Cause the Store to Stop Responding.
For more information about how to use the LDP tool, see Microsoft Knowledge Base article 260745, XADM: Using the LDP Utility to Modify Active Directory Object Attributes.
For more information about how to work with ADSI Edit, see the topic "Adsiedit.msc: ADSI Edit" in the Windows Server Help.