KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q196745: Very Slow Paged Pool Leak in Windows NT 4.0

Article: Q196745
Product(s): Microsoft Windows NT
Version(s): winnt:4.0
Operating System(s): 
Keyword(s): kbWinNT400sp4fix
Last Modified: 10-AUG-2001

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Windows NT Server version 4.0 
- Microsoft Windows NT Workstation version 4.0 
- Microsoft Windows NT Server version 4.0, Terminal Server Edition 
-------------------------------------------------------------------------------

SYMPTOMS
========

After a Windows NT server has been running at least a week, the following event
may show up in the System event log:

  EVENT: 2020 SOURCE:SRV
  TEXT: The server was unable to allocate from the system paged pool because the
  pool was empty.

Or, by other troubleshooting methods or by using Performance Monitor, you observe
that the paged pool memory counter is higher than it has been under previous
observations. Observing for several days, you do not observe any real changes
but, by observing the system for weeks, the trend is always up.

This leak occurs on servers with many users more than 100 and many groups greater
than 10 for each user. It is not related to the relative load on the server.

CAUSE
=====

Under certain conditions, the NetSessionEnum and NetUserGetLocalGroups NET APIs
leak memory in both the calling application private bytes and paged pool memory.
This leak is very difficult to track down as it is very slow to show up.

RESOLUTION
==========

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or
Windows NT Server 4.0, Terminal Server Edition. For additional information,
please see the following article in the Microsoft Knowledge Base:

  Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

STATUS
======

Microsoft has confirmed this to be a problem in Windows NT 4.0 and Windows NT
Server 4.0, Terminal Server Edition. This problem was first corrected in Windows
NT 4.0 Service Pack 4 and Windows NT Server 4.0, Terminal Server Edition,
Service Pack 4.


Additional query words:

======================================================================
Keywords          : kbWinNT400sp4fix 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbNTTermServ400 kbNTTermServSearch
Version           : winnt:4.0
Issue type        : kbprb
Solution Type     : kbfix

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.