Large Write_Andx messages

George Colley gcolley at apple.com
Tue Oct 30 15:38:34 GMT 2007


I think this has been cleared up, but here is my 2 cents worth.  
Chaining writes to a Windows Server is a bad thing, they don't handle  
it very well. You could end up blue screen the server. If you are look  
for performance with Windows then 60K writes is the best you can do,  
if so one knows a better number I would love to here about it. If you  
are doing singing then you can't do CAP_LARGE_WRITEX with Windows  
Server. The CAP_LARGE_READX will continue to work.
George
On Oct 29, 2007, at 12:31 PM, Christopher R. Hertel wrote:

> Ah.
>
> Thanks for clarifying.  Jeremy understood it right...
>
> I have never seen WRITE_ANDX chains.  Samba is probably able to  
> handle them
> but you would have to test.
>
> Note that CAP_LARGE_WRITEX does not refer to ANDX chains, but rather  
> to
> large writes that exceed the negotiated block size.
>
> Chris -)-----
>
> Mikael Klamra wrote:
>> Hi,
>> I was asking about chained WRITE_ANDX messages. Windows supports  
>> large
>> WRITE_ANDX messages when the messages contain only one block.  
>> However,
>> I want to chain several blocks in a message (i.e., use the batching
>> functionality of WRITE_ANDX). Windows Server 2003 seems to accept
>> WRITE_ANDX messages containing two blocks when the total message size
>> is up to about 4700 bytes. When the size gets larger, the server
>> returns a non-specific error code. This usually means that the  
>> message
>> has the wrong format or that a capability was not set. Does Samba use
>> the batching functionality of WRITE_ANDX? The Windows client does not
>> seem to use it.
>>
>> Mikael
>>
>>
>> On 10/29/07, Christopher R. Hertel <crh at ubiqx.mn.org> wrote:
>>> Jeremy Allison wrote:
>>>> On Mon, Oct 29, 2007 at 11:20:43AM -0700, James Peach wrote:
>>>>> The Mac OS X 10.5 client will do large reads and writes to  
>>>>> Samba. The
>>>>> Samba support for this works perfectly well.
>>>> He wasn't asking about large read/writes, he was asking about
>>>> chaining (andX) support.
>>> Actually, he's asking about both to some extent.
>>>
>>> He pinged me first in reference to my book and then also the jCIFS  
>>> list.
>>> These are interesting questions, of course, but I think the  
>>> original post
>>> slid a bit between CAP_LARGE_WRITEX and the idea of chaining  
>>> WRITE_ANDX
>>> messages, thus the confusion.
>>>
>>> Chris -)-----
>>>
>>> --
>>> "Implementing CIFS - the Common Internet FileSystem"    ISBN:  
>>> 013047116X
>>> Samba Team -- http://www.samba.org/    -)-----     Christopher R.  
>>> Hertel
>>> jCIFS Team -- http://jcifs.samba.org/  -)-----  ubiqx development,  
>>> uninq
>>> ubiqx Team -- http://www.ubiqx.org/    -)-----          crh at ubiqx.mn.org
>>> OnLineBook -- http://ubiqx.org/cifs/   -)-----             crh at ubiqx.org
>>>
>
> -- 
> "Implementing CIFS - the Common Internet FileSystem"    ISBN:  
> 013047116X
> Samba Team -- http://www.samba.org/    -)-----     Christopher R.  
> Hertel
> jCIFS Team -- http://jcifs.samba.org/  -)-----  ubiqx development,  
> uninq
> ubiqx Team -- http://www.ubiqx.org/    -)-----          crh at ubiqx.mn.org
> OnLineBook -- http://ubiqx.org/cifs/   -)-----             crh at ubiqx.org



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