1. Start the Exchange Management Console.
2. In the console tree, expand Server Configuration, and then click Mailbox.
3. In the work pane, right-click the storage group for which you want to enable or disable circular logging, and then click Properties. The <Storage Group Name> Properties dialog box appears.
4. Select or clear the Enable circular logging check box.
5. Click OK.
6. To make your changes to the circular logging settings effective, restart the Microsoft Exchange Information Store service, or dismount and then mount all of the databases in the storage group.