Why SMB2 need asynchronous architecture ?

[Jim]

Volker Lendecke <Volker.Lendecke <at> SerNet.DE> writes:

> 
> On Thu, May 30, 2013 at 11:57:59PM +0000, Jim wrote:
> > 
> > Start from samba-3.6, SMB2 use asynchronous architecture. 
> > 
> > I don't understand why it benefits the performance of network 
application in 
> > Windows 7,  and what kinds of network application can be benefited ?
> > 
> > In my testing in windows7, SMB2 performance is worse than SMB1. (Test 
with 
> > explorer and robocopy)
> 
> In theory, SMB2 has larger packets and less requests,
> leading to higher performance. We have seen reports that
> SMB2 is slower because by default signing is being used in
> SMB2 and not in SMB1. Can you check that?
> 
> If that is not the case for you, we need to see why you are
> seeing worse performance with SMB2.
> 
> Volker
> 

Hi, Volker:
     
     I use the following command to do the test.
     robocopy %pc_source%\5GB %syno_target%\ /E /IS /NS /NC /NP /NFL /NDL 

     I think signature is off because 'Signature' value of SMB2 header is 
always 0 during the test. 

     Test environment:
          - CPU: Intel Atom CPU D2700, DDR3 1GB.
          - Samba version is 3.6.9

     I didn't enable AIO, all the other configuration is by default.

     I've test IOMeter on 10G network, the CPU usage of SMB2 is always 100%, 
but SMB1 about 8x%.  SMB2 seems cost more resource than SMB1.


Thanks,
Jim