DOCUMENT:Q191098  09-AUG-2001  [winnt]
TITLE   :Large File Copy Operation Causes Available Bytes to Drop
PRODUCT :Microsoft Windows NT
PROD/VER:WinNT:4.0
OPER/SYS:
KEYWORDS:kbWinNT400sp4fix

======================================================================
-------------------------------------------------------------------------------
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
========

A large file copy operation causes available bytes to drop significantly. This
happens when a Windows client copies a large file from or to a Windows NT
computer.

In this case, you will notice a user interface performance degradation. The files
need to be about the size of the physical memory of the computer or greater.

If you look at performance counters while this happens, you find that the counter
for the file cache (Memory: Cache Bytes) goes up while the process working sets
(Process: Working Set, instance _Total) decline. Available bytes (Memory:
Available Bytes) declines in the inverse proportion of the cache bytes.

CAUSE
=====

While copying the files, Windows clients do not use the flag
FILE_FLAG_SEQUENTIAL_SCAN to open the files. Thus, Cache Manager tries to cache
the whole file in memory and causes the file cache to grow and, thus, available
bytes to drop.

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 4.0 and Windows NT Server 4.0, Terminal Server Edition
Service Pack 4.
======================================================================
Keywords          : kbWinNT400sp4fix 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbNTTermServ400 kbNTTermServSearch
Version           : WinNT:4.0
Hardware          : ALPHA x86
Issue type        : kbbug
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.

Copyright Microsoft Corporation 2001.