Topic Last Modified: 2005-11-17

The Microsoft® Exchange Server Analyzer Tool queries two Microsoft Windows® Management Instrumentation (WMI) classes to determine the amount of physical memory in the Active Directory® directory server, and the amount of virtual address space allocated to user mode processes. The following table describes the classes and keys being evaluated by the Exchange Server Analyzer.

Class Key Description

Win32_OperatingSystem

MaxProcessMemorySize

Maximum number of kilobytes of memory that can be allocated to a process.

Win32_OperatingSystem

OSProductSuite

Installed and licensed system product additions to the operating system.

Win32_ComputerSystem

TotalPhysicalMemory

Number of bytes of random access memory (RAM) installed in the computer.

If the Exchange Server Analyzer determines that the directory server has less than 950 MB of RAM, and that the value for the MaxProcessMemorySize is more than 2097024 but less than 3104640, a warning is displayed.

This warning indicates that the directory server is not correctly configured for optimal memory usage. The /3GB startup switch has been set on this computer and should be removed. This switch should only be used on Active Directory servers with 1 GB or more of memory that are running any of the following operating systems:

Important:
The /3GB switch should not be used on Windows 2000 Server because it is unsupported and can cause application or operating system crashes. Furthermore, the /3GB switch is only supported on the above operating systems when 1 GB or more of physical memory is installed.

If you encounter this warning on a system in which 1 GB of physical memory is installed, it could indicate that another component, such as a video card, has been allocated some of this physical memory at the hardware level, thereby making the allocated physical memory unavailable to the operating system. In these cases, the amount of memory installed physically according to Windows will be less than the actual amount of physical memory installed in the computer. If you encounter this situation, you should compare the amount of installed memory reported by the BIOS with the amount of installed memory reported by Windows.

To correct this warning on Windows Server 2003

  1. Right-click My Computer, and then click Properties. The System Properties dialog box appears.

  2. Click Advanced.

  3. In the Startup and Recovery area, click Settings. The Startup and Recovery dialog box appears.

  4. In the System startup area, click Edit. This will open the Windows Boot.ini file in Notepad.

  5. In the [Operating Systems] section, delete the following switch from all startup lines: /3GB

  6. Save the changes and close Notepad.

  7. Click OK twice to close the open dialog boxes, and then restart the computer for the change to take effect.

To correct this warning on Windows 2000 Server

  1. In Windows Explorer, navigate to the system partition.

  2. If you cannot see the Boot.ini file, it could be because the Folder Options are set to Hide protected operating system files. If this is the case, in Explorer, click Tools, Folder Options, and then click View. Clear the Hide protected operating system files (Recommended) check box. When prompted with the warning box, click Yes.

  3. When the Boot.ini file is visible in Explorer, right-click the file, click Open With, and click Notepad to open the file.

  4. In the [Operating Systems] section, delete the following switch from all startup lines: /3GB

  5. Save the changes and close Notepad.

  6. Restart the computer for the change to take effect.

For further details about using the /3GB startup switch, see the following Microsoft Knowledge Base articles: