windows 2000: slow file copy from windows 2000 to SAMBA

Wed May 23 15:59:37 GMT 2001

Quick question on this.  Is your Samba server in security=server mode?  
This may be related to another problem I am studying so I would really 
like to know.

Thanks!

Chris -)-----

> Greetings,
> 
> I have a interesting problem copying large files from a Windows2000 server
> to a SAMBA share. The copy takes extremely long. For example, a 600K file
> takes in excess of 40 seconds. Initially, we had the problem copy the file
> to NT 4 machines as well, but we fixed it with the following work around
> which explains the problem well:
> 
> Is there a way we can apply the same "FIX" to samba?
> 
> Regards,
> Chris
> 
> 
> 
> 		Q279282 - Slow File Write from Windows 2000 to Windows NT
> 4.0 Server 
> 		 Excerpt from this page:The file-copy write process from a
> Windows 2000 Professional-based computer to a Windows NT 4.0 Server-based
> computer may take up to four times longer than reading the same files from
> Windows NT Server. The Windows 2000 workstation redire(size 9780 bytes,
> updated 4/11/2001 4:19:00 AM GMT 
> 
> 		Slow File Write from Windows 2000 to Windows NT 4.0 Server 
> 
> 	
> ----------------------------------------------------------------------------
> ----
> 		The information in this article applies to:
> 
> 		Microsoft Windows NT Server version 4.0 
> 		Microsoft Windows 2000 Advanced Server 
> 		Microsoft Windows 2000 Datacenter Server 
> 		Microsoft Windows 2000 Professional 
> 		Microsoft Windows 2000 Server
> 
> 	
> ----------------------------------------------------------------------------
> ----
> 		IMPORTANT: This article contains information about editing
> the registry. Before you edit the registry, make sure you understand how to
> restore it if a problem occurs. For information about how to do this, view
> the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a
> Registry Key" Help topic in Regedt32.exe.
> 
> 
> 		SYMPTOMS
> 		The file-copy write process from a Windows 2000
> Professional-based computer to a Windows NT 4.0 Server-based computer may
> take up to four times longer than reading the same files from Windows NT
> Server. 
> 
> 
> 
> 		CAUSE
> 		The Windows 2000 workstation redirector does not support RAW
> SMB mode. Instead, Windows 2000 uses Large File (CAP_LARGE_FILE) support,
> which is just as fast. However, not all earlier operating systems implement
> Large File support. For example, Windows NT 4.0 has Large File Read support,
> but not Large File Write support. 
> 
> 
> 
> 		RESOLUTION
> 		WARNING: Using Registry Editor incorrectly can cause serious
> problems that may require you to reinstall your operating system. Microsoft
> cannot guarantee that problems resulting from the incorrect use of Registry
> Editor can be solved. Use Registry Editor at your own risk.
> 
> 		For information about how to edit the registry, view the
> "Changing Keys and Values" Help topic in Registry Editor (Regedit.exe) or
> the "Add and Delete Information in the Registry" and "Edit Registry Data"
> Help topics in Regedt32.exe. Note that you should back up the registry
> before you edit it. If you are running Windows NT or Windows 2000, you
> should also update your Emergency Repair Disk (ERD).
> 
> 		To work around this performance issue, make the following
> registry change on the Windows NT 4.0-based server: 
> 
> 		Start Registry Editor (Regedt32.exe).
> 
> 
> 		Locate and click the following key in the registry:
> 
> 
> 	
> HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\lanmanserver\parameters
> 
> 		On the Edit menu, click Add Value, and then add the
> following registry value:
> 
> 
> 		Value Name: SizReqBuf
> 		Data Type: DWORD Value
> 		Radix: Decimal
> 		Value: 65535 
> 		Quit Registry Editor.
> 
> 
> 		Restart the server.
> 
> 
> 		After you make this change, the performance of the write
> process is approximately the same as a read operation between the two
> computers. 
> 
> 		Note that the SizReqBuf value controls the buffer size for
> CORE SMB requests. Setting it to 64 KB has approximately the same effect as
> Large Write support, which uses 60-KB buffers. 
> 
> 		NOTE: This adjustment causes the server services to use more
> memory. 
> 
> 
> 
> 		MORE INFORMATION
> 		Windows 2000 read operations are fast because they use the
> SMB Large Read capability of Windows NT Server (CAP_LARGE_READX). Windows NT
> Server does not support CAP_LARGE_WRITEX. For more information, see the
> "Common Internet File System (CIFS)" specification at the following
> Microsoft Web site: 
> 
> 	
> http://msdn.microsoft.com/workshop/networking/cifs/default.asp
> 		File-copy operations from Windows 2000 to Windows 2000 work
> quickly. They use CAP_LARGE_READX and CAP_LARGE_WRITEX capabilities to send
> files in 60-KB portions. Also, file-copy operations from Windows NT to
> Windows NT work quickly. They use CAP_RAW_MODE to send files in 64-KB
> portions. For additional information, click the article numbers below to
> view the articles in the Microsoft Knowledge Base: 
> 		Q99234 History of SizeReqBuf Changes 
> 		Q223140 SMB Size Negotiation When Copying Files with Windows
> NT Explorer 
> 
> 		Additional query words: 
> 
> 		Keywords : kbenv 
> 		Issue type : kbprb 
> 		Technology : kbWinNTsearch kbwin2000AdvServSearch
> kbwin2000DataServSearch kbWinNTSsearch kbwin2000Ssearch kbwin2000ProSearch
> kbExchange400 kbWinAdvServSearch kbWinDataServSearch
> 
> 
> Chris Coupal
> EDS Canada
> Information Services Corporation of Saskatchewan
> (306) 787-0126
> chris.coupal at eds.com
> 
> 

-- 
Christopher R. Hertel -)-----                   University of Minnesota
crh at nts.umn.edu              Networking and Telecommunications Services

    Ideals are like stars; you will not succeed in touching them
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