[Samba] SMB2 write performace slower than SMB1 in 10Gb network

Wed May 2 02:30:42 MDT 2012

On Wed, May 02, 2012 at 04:06:15PM +0800, Zhiming Zhou wrote:
> 于 2012/4/28 14:58, Volker Lendecke 写道:
> >On Sat, Apr 28, 2012 at 01:46:35PM +0800, Zhiming Zhou wrote:
> >>I use Iometer to test normal file read/write performance,
> >>at first, SMB2 is not enabled,test 1MB sequential read/write performance
> >>with SMB1, I got 610 MB/s write performance which
> >>is really good, while read performance is just 280 MB/s.
> >>
> >>Then I change "max protocol" to "SMB2" in smb.conf to enable
> >>SMB2, other configs in smb.conf are not changed, restart samba,
> >>reconnect in Windows 2008, use Iometer to run test again, I got
> >>  470 MB/s write performance and 505 MB/s read performance.
> >>
> >>It's quite good that read performance bursts with SMB2, but
> >>write performace droped by 140 MB/s, I run this write test
> >>serveral times again, write performance indeed droped a lot,
> >>so is it normal that SMB2 write performance is slower than
> >>SMB1?
> >No, this is not normal. Maybe you want to enable async I/O.
> >Depending on the platform, plain aio might work with
> >
> >aio write size = 1
> >
> >It might be a good idea to also enable
> >
> >vfs objects = aio_fork
> >
> >With latest Samba Jeremy Allison has also added the
> >aio_pthread module, but that is not yet in released code.
> >You can get it from the latest v3-6-test branch in our git
> >repository.
> >
> >With best regards,
> >
> >Volker Lendecke
> 
> Tested SMB2 write peformance again under 10Gb network with AIO
> enabled, I set
> 
> aio write size = 1
> 
> and got 332.17 MB/s output, which is slower than previous 470 MB/s
> (AIO disabled),
> enable aio_fork vfs object, test result is almost the same.
> 
> In my opinion, SMB2 write should be faster than SMB1 even when AIO
> is disabled,
> isn't it?

Yes, it should. Sorry for pointing you into the wrong
direction.

With best regards,

Volker Lendecke

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