Samba 4.1.9 and outstanding AIO requests

[Krishna Harathi]

Hi Volker,

I am using FIO. No, Samba does not behave differently than a Windows
server.

Given that 1MB transfers take 16 credits, and default max credits are 128,
with AIO I should see 8 write
requests (at least two or more, at least at the beginning before the
pipeline is filled) without waiting for a response.
I am not seeing this behavior with FIO.

But in my last run with simple drag-and-drop copy from a W8 client, I got
the behavior I wanted. I have
now set "MaxCredits" registry entry set to 256, but I am not sure if it
matters.

You guys are awesome, I am sure you all can make Samba as fast (if not
better) than Windows server.

Regards.
Krishna Harathi


On Fri, Jul 25, 2014 at 3:23 AM, Volker Lendecke <Volker.Lendecke at sernet.de>
wrote:

> Hi!
>
> What application do you use on the client to trigger this?
> Does the Windows client behave differently against a Windows
> Server? If so, can you take comparative network traces, so
> that we can see where we behave differently? And, what
> do you exactly mean by "only 2 outstanding IO requests"?
>
> Maybe Samba is so fast it replies quickly enough? (just
> kidding :-)
>
> Volker
>
> On Thu, Jul 24, 2014 at 02:44:07PM -0700, Krishna Harathi wrote:
> > Jones,
> >
> > Thanks for responding with the options, tried with aio_pthread, did not
> > make a difference.
> >
> > I also tried a W8 client connected to a W2007 server and the result is
> the
> > same,
> >
> > What I noticed  in all these cases is that during SMB2 session setup W8
> > SMB2 client is setting (requesting) "Credits' field to 31.
> > Samba as well as W2007 server is returning the same Credits = 31 in  the
> > session response.
> >
> > Question - Is it this value that dictates how many outstanding AIO
> possible?
> >
> >                  - I tried setting windows client registry
> "Smb2CreditsMin"
> > to 512 ,and rebooted the client and tested again,  but made no
> difference.
> >
> > Any help in getting > 2 AIO requests is appreciated.
> >
> >
> > Regards.
> > Krishna Harathi
> >
> >
> > On Wed, Jul 23, 2014 at 4:35 AM, Jones <jones.kstw at gmail.com> wrote:
> >
> > > Hello Krishna,
> > >
> > > 2014-07-23 14:13 GMT+08:00 Krishna Harathi <kharathi at exablox.com>:
> > >
> > > We used the default implementation as well as aio_posix VFS module.
> > >
> > >
> > > Perhaps could use aio_pthread or aio_fork instead of aio_posix,
> > > for example:
> > > [global]
> > > aio read size = 1
> > > aio write size = 1
> > > vfs objects = aio_pthread
> > >
> > > reference:
> > >
> > >
> http://www.snia.org/sites/default/files2/SDC2012/presentations/Revisions/JeremyAllison_The_Evolution_of_Samba-ion.pdf
> > >
> > > --
> > > Regards,
> > > Jones
> > >
>
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