Microsoft KB Archive/885936

= Files saved to a mapped network share from Windows XP are corrupted =

Article ID: 885936

Article Last Modified on 8/29/2007

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APPLIES TO


 * Microsoft Windows XP Professional
 * Microsoft Windows XP Home Edition
 * Microsoft Windows XP Service Pack 2
 * Microsoft Windows XP Service Pack 2
 * Microsoft Windows XP Service Pack 1

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SYMPTOMS
When you try to save a file from a Microsoft Windows XP-based computer to a network share on a Windows-based server, the saved file may be corrupted. Typically, the saved file contains zeros in the end of the file instead of the expected data.



CAUSE
This problem may occur when you use a program that memory maps a file that is not flagged for write caching, and a set end of file is received from the program. This problem occurs when one of the following conditions is true for the client computer that you use to save the file:  Microsoft Windows XP Service Pack 2 is installed. The hotfix that is described in the following Microsoft Knowledge Base article is installed:

811169 Update to increase the performance of the Network Redirector



In this scenario, the cache is not flushed before the view of the file is unmapped.



WORKAROUND
To work around this problem, disable opportunistic locks on the server where you are saving the file. To do this, set the EnableOplocks registry value to &quot;0&quot; in the following registry subkey:

To do this, follow these steps:  Click Start, click Run, type regedit, and then press ENTER. Locate and then click the following registry subkey:

 

 If the EnableOplocks value is not present in the right pane, you must create it. To do this, follow these steps: <ol style="list-style-type: lower-alpha;"> Right-click Parameters in the left pane, point to New, and then click DWORD Value.</li> Type EnableOplocks to name the value, and then press ENTER.</li></ol> </li> Right-click EnableOplocks, and then click Modify.</li> In the Value data box, type 0, and then press ENTER.</li> Quit Registry Editor.</li></ol>

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Hotfix information
A supported hotfix is now available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. To create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

File information
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel. <pre class="fixed_text">  Date         Time    Version          Size      File name 23-Nov-2004 23:33   5.1.2600.2569    174,592   Rdbss.sys

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STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.

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MORE INFORMATION
For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Keywords: kbbug kbfix kbqfe kbwinxpsp2fix kbwinxppresp2fix kbhotfixserver KB885936

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