Microsoft KB Archive/933998

= Event ID 2020 error messages are logged in the System log, and you experience decreased performance on a server that is running Windows Server 2003 or Windows 2000, =

Article ID: 933998

Article Last Modified on 4/16/2007

-

APPLIES TO


 * Microsoft Windows Server 2003, Enterprise Edition (32-bit x86)
 * Microsoft Windows Server 2003, Standard Edition (32-bit x86)
 * Microsoft Windows 2000 Advanced Server
 * Microsoft Windows 2000 Server

-



Important This article contains information about how to modify the registry. Make sure that you back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows registry



SYMPTOMS
You experience decreased performance on a computer that is running Microsoft Windows Server 2003 or Microsoft Windows 2000. The computer may eventually stop responding (hang). Additionally, you experience the following symptoms:  Event ID error messages that resemble the following are logged in the System log:

Event ID 2020

Type: Error

Source: Srv

Description: The server was unable to allocate from the system paged pool because the pool was empty.

 The Memory Pool Monitor (Poolmon.exe) tool shows high usage of the MmST tag.



CAUSE
This problem occurs if a memory leak occurs, and then paged pool memory is exhausted.



RESOLUTION
Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

To help resolve this issue, modify the registry to configure the following tuning changes to the computer:
 * Throttle the Server service.
 * Maximize the total amount of available paged pool memory.
 * Prevent the computer from using all available physical memory for file caching.
 * Prevent stale network connections to the server from using resources.

To do this, follow these steps:  Click Start, click Run, type regedit, and then click OK.

Note The remaining steps describe how to add registry entries and then how to set the registry entries to a specific value. Create the registry entries only if they do not already exist on the computer. If the registry entries already exist, set the entry to the appropriate value. Throttle the Server service by configuring the MaxMpxCt, SizReqBuf, and Autodisconnect registry entries in the following registry subkey:

To do this, follow these steps:  Locate and then click the following registry subkey:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\lanmanserver\Parameters

</li> On the Edit menu, point to New, and then click DWORD Value.</li> Type MaxMpxCt, and then press ENTER.</li> Double-click MaxMpxCt, click Hexadecimal, type 0000000A in the Value data box, and then click OK.</li> On the Edit menu, point to New, and then click DWORD Value.</li> Type SizReqBuf, and then press ENTER.</li> Double-click SizReqBuf, click Hexadecimal, type 00001000 in the Value data box, and then click OK.</li> On the Edit menu, point to New, and then click DWORD Value.</li> Type Autodisconnect, and then press ENTER.</li> Double-click Autodisconnect, click Hexadecimal, type 00000000 in the Value data box, and then click OK.</li></ol> </li> Maximize the total amount of available paged pool memory, and prevent the computer from using all available physical memory for file caching. To do this, configure the PoolUsageMaximum, PagedPoolSize, and LargeSystemCache registry entries in the following registry subkey:

To do this, follow these steps: <ol style="list-style-type: lower-alpha;"> Locate and then click the following registry subkey

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Memory Management

</li> On the Edit menu, point to New, and then click DWORD Value.</li> Type PoolUsageMaximum, and then press ENTER.</li> Double-click PoolUsageMaximum, click Hexadecimal, type 00000028 in the Value data box, and then click OK.</li> Double-click PagedPoolSize, click Hexadecimal, type ffffffff in the Value data box, and then click OK.</li> On the Edit menu, point to New, and then click DWORD Value.</li> <li>Type LargeSystemCache, and then press ENTER.</li> <li>Double-click LargeSystemCache, click Hexadecimal, type 00000000 in the Value data box, and then click OK.</li></ol> </li> <li>Prevent stale network connections to the server from using resources by configuring the TcpTimedWaitDelay registry entry in the following registry subkey:

To do this, follow these steps: <ol style="list-style-type: lower-alpha;"> <li>Locate and then click the following registry subkey:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

</li> <li>On the Edit menu, point to New, and then click DWORD Value.</li> <li>Type TcpTimedWaitDelay, and then press ENTER.</li> <li>Double-click TcpTimedWaitDelay, click Hexadecimal, type 0000001e in the Value data box, and then click OK.</li></ol> </li></ol>

<div class="moreinformation_section">

MORE INFORMATION
For more information about how to troubleshoot issues in which event ID 2020 error messages are logged in the System log, click the following article numbers to view the articles in the Microsoft Knowledge Base:

312362 Server is unable to allocate memory from the system paged pool

891957 Update is available that fixes various Volume Shadow Copy Service issues in Windows Server 2003

815493 Paged pool memory leak with increase in handle count for Services.exe

886670 Event 2020 is logged and your Windows Server 2003-based file server stops responding

891004 You may experience a paged pool memory leak when many clients create, copy, and delete files on an NTFS partition in Windows Server 2003

912376 How to monitor and troubleshoot the use of paged pool memory in Exchange Server 2003 or in Exchange 2000 Server

Keywords: kbtshoot kbexpertiseinter kbprb KB933998

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.