[OpenAFS] Windows client network behaviour

Anders Magnusson ragge@ltu.se
Thu, 22 Sep 2011 17:05:59 +0200


On 09/22/2011 03:00 PM, Jeffrey Altman wrote:
> On 9/22/2011 5:08 AM, Anders Magnusson wrote:
>    
>> What I meant here is that the gateway is a Centos 5 machine running
>> Samba and OpenAFS 1.4.10 and store data in AFS.  So, writing to the
>> same place in AFS via this machine is significantly faster than using
>> the IFS client. This is just to show that the performance problem isn't
>> there if using the Linux client.
>>      
> If the behavior you are seeing is not a regression from the OpenAFS
> Windows 1.6.0 client on your systems, then the performance limitation is
> simply a design limitation of the current Windows cache manager
> implementation.  The cache manager currently requires that all StoreData
> operations be serialized which limits the number of simultaneous
> StoreData RPCs on a file to 1.  Small chunksizes will result in poor
> performance.   I use
>
>    ChunkSize 23 (decimal)
>
> which equates to 8MB per RPC.
>    
I have tested with the 1.6.0 client, and get about double speed compared 
to the IFS client.

I also tried to increase the chunksize as suggested, but no difference 
in performance.

So, this is still a mystery for me :-/

-- Ragge