Microsoft KB Archive/290861

= No Error Message When Copying to Full Samba Volume =

Article ID: 290861

Article Last Modified on 11/1/2006

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APPLIES TO


 * Microsoft Windows NT Server 4.0 Standard Edition
 * Microsoft Windows NT Workstation 4.0 Developer Edition

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This article was previously published under Q290861



IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry



SYMPTOMS
When you copy or move files from a Windows NT 4.0-based computer to a Samba server, the file may be truncated if the Samba server's hard disk is full or nearly full. This can also occur if the Samba server uses quotas and you would be exceeding the allocated disk space by having the file on the Samba share.

The copy or move operation appears to succeed because Windows NT does not display any error messages; however, some data at the end of the file may be lost.



CAUSE
This behavior occurs when the amount of free space on the Samba share is slightly smaller than the size of the file. In this scenario, Windows NT might not catch an error message that is sent near the end of the write operation.



RESOLUTION
WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

To resolve this behavior:  Install Service Pack 4 (SP4) or later on your computer, if you have not yet done so. Start Registry Editor (Regedt32.exe). Locate and click the following key in the registry:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Rdr\Parameters

 On the Edit menu, click Add Value, and then add the following registry value:

Value name: UseWriteBehind

Data type: REG_DWORD

Value data: 0

 Quit Registry Editor.</ol>

If you set the UseWriteBehind value to 0, this disables the write-behind redirector optimization for write-only files. The default setting is to use the write-behind optimization.

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MORE INFORMATION
If you have not yet installed SP4 or later, you will receive the errors that are referred to in the following Microsoft Knowledge Base articles after you disable write-behind:

169742 Semaphore Timeout Error When UseWriteBehind Disabled

216795 Semaphore Error After Disabling Write Behind Caching

Samba is an open-source software suite that provides file and print services to SMB/CIFS clients.

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