How to Disable Network Redirector File Caching (163401)

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

While data is being transferred to a remote server, you may experience one of the following error messages:

Event ID 26:
Application popup: System process-lost delayed write data: the system was attempting to transfer file data from buffers to <filename path>. The write operation failed and only some of the data may have been written to the file.

-or-

Event ID 26
Application popup: System process-lost delayed write data: the system was attempting to transfer file data from buffers to <network share>. The write operation failed and only some of the data may have been written to the file.

These popup messages may also be accompanied by one or more of the following event log messages:

Event ID: 3013
Description: The redirector has timed out to <Servername>

-or-

Event ID: 8007
Description: NetWare redirector timed out its request to server <Servername>

CAUSE

By default, when the Microsoft Windows NT redirector opens a file for read or read/write access, the redirector utilizes the Windows NT system cache. Therefore, when data is written to the file, it is written to the cache and not immediately flushed to the redirector. The cache manager flushes the data at a later time. If an unrecoverable network error occurs while the data is being transferred to the remote server, it may cause the write request to fail and the above application popup to occur.

RESOLUTION

WARNING: This procedure should first be tested in a non-critical environment before being implemented into a production environment. In general, this change slows down network I/O.

You can disable Network Redirector File Caching by performing the following steps:

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.

Start Registry Editor (Regedt32.exe) and go to the following subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Rdr\Paramete
Click Add Value on the Edit menu.
Enter the following:
```
Value Name: UseWriteBehind
Data Type:  REG_DWORD
Data:       0
						
```
1-true 0-false (default: 1)

UseWriteBehind - Enables the write-behind optimization for write Only files.
Go to the following subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services \Lanmanworkstation\paramete
Click Add Value on the Edit menu.
Enter the following:
```
Value Name: UtilizeNTCaching
Data Type:  REG_DWORD
Data:       0
						
```
1-true 0-false (default: 1)

UtilizeNTCaching - Indicates whether the redirector uses the cache manager to cache the contents of files. Disable this parameter only to guarantee that all data is flushed to the server immediately after it is written by the application.
Shut down and restart your computer.

MORE INFORMATION

When implementing this change in the registry, it is possible for the mail flow to be disrupted between Microsoft Exchange and Microsoft Mail using the Microsoft Mail Connector if there is an underlying network problem or a slow link. If the change above is made, the mail error will be manifested in the form of an NDR stating:

[005] Mail retry count exceeded Network/Postoffice

Once this registry entry is changed back to the default, mail should flow once again. However, the events will again begin to be registered in Event Viewer.