Exchange server running SQL Server

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at]  

Topic Last Modified: 2009-09-08

The Microsoft® Exchange Server Analyzer Tool queries the Win32_Service Microsoft Windows® Management Instrumentation (WMI) class to determine the value of the Started key for the Microsoft SQL Server™ service (MSSQLSERVER). A value of True indicates that the SQL Server service is running on this Exchange server.

The Exchange Server Analyzer also queries the Win32_OperatingSystem WMI class to determine the value for the OSProductSuite key. The value returned for this key indicates the version of Windows operating system that is running on the Exchange Server computer.

Additionally, the Exchange Server Analyzer also queries the Active Directory® directory service to determine the count of the entries listed in the homeMDBBL attribute of each mailbox store. The count of this attribute represents the number of mailboxes on the mailbox store.

If the Exchange Server Analyzer determines that the SQL Server service is started on an Exchange Server computer that meets all the following criteria, a warning is displayed:

  • The Exchange Server computer hosts more than 100 mailboxes.

  • The Exchange Server computer is not running on Windows Small Business Server 2008, Windows Small Business Server 2003, or Small Business Server 2000.

Running SQL Server on the same computer as a production Exchange mailbox server is not recommended. Both SQL Server and Exchange mailbox servers consume a large amount of memory and disk resources to operate optimally. Co-hosting SQL Server and Exchange Server on the same computer in a production environment will likely lead to poor performance by one or both of the servers. Additionally, troubleshooting and securing such an installation is not well understood.

Finally, there are a number of known interoperability issues that you may encounter if you are running SQL Server and Exchange Server on the same computer. Most of these issues are the result of version inconsistencies with files or programs common to the two servers, such as Microsoft Distributed Transaction Coordinator (MS DTC), Microsoft ActiveX® Data Objects (ADO), and OLE Database (OLE DB).

To correct this warning

  • You should consider one of the following options to correct this warning:

    • Move either Exchange Server or SQL Server off the computer. Completely removing one of these programs from the computer is recommended.

    • Move the Exchange mailboxes off the server. At a minimum, you should remove the mailboxes and convert the Exchange server to a protocol or infrastructure server. This will reduce the load considerably for disk I/O and marginally for CPU (the latter is dependent on the Exchange infrastructure role).

    • Consider installing Small Business Server instead. If you are running Exchange in a small environment where you do not require more than one Exchange server, you may benefit from installing Small Business Server. Small Business Server includes both SQL Server and Exchange Server, along with other core Microsoft server applications and has been developed, tested, and optimized for a single-computer installation.

For more information about moving mailboxes and Exchange servers, see the following Microsoft Knowledge Base articles:

For more information about Small Business Server, see "Microsoft Windows Small Business Server 2003" (,