How to Set the DB Data Buffers per Object Registry Value


Topic Last Modified: 2005-05-10

The DB data buffers per object registry value is the number of 4-KB database server buffers that are configured for each database object. More buffers require more memory, but make it less likely for a database object to be rolled out to disk because of a lack of buffer space. One recommended reason for changing this value is in the case when a Message Transfer Agent (MTA) communicates with multiple Exchange Server 5.5 computers either within or between sites. You should also tune this value if another messaging connector is homed on this server. In these scenarios, it is recommended that you change the value data for DB data buffers per object to 6. If this MTA does not communicate with multiple Exchange 5.5 computers within or between sites, it is recommended that the default setting of 3 be used.

In smaller organizations, the MTA process typically does not require manual tuning. After you have converted to Native Mode, you should remove these registry settings. Using the MTA tuning described below in a Native Mode Exchange organization decreases the performance of Exchange.

Before you perform the procedure in this topic, be aware that the procedure contains information about editing the registry.

Incorrectly editing the registry can cause serious problems that may require you to reinstall your operating system. Problems resulting from editing the registry incorrectly may not be able to be resolved. Before editing the registry, back up any valuable data.

  1. Open a registry editor, such as Regedit.exe or Regedt32.exe.

  2. Navigate to HKLM\System\CurrentControlSet\Services\MSExchangeMTA\Parameters.

  3. In the details pane, locate and double-click DB data buffers per object.

  4. In the Value data field, enter the appropriate value, and click OK.

  5. Close the registry editor and restart the Microsoft Exchange MTA Stacks service for the change to take effect.

For information about how to edit the registry, see Microsoft Knowledge Base article 256986, "Description of the Microsoft Windows Registry" (