Poor Samba throughput on 6.0

[Joao Barros]

On 11/10/05, Joao Barros <joao.barros at gmail.com> wrote:
> On 11/10/05, Robert Watson <rwatson at freebsd.org> wrote:
> > On Wed, 9 Nov 2005, Mike Jakubik wrote:
> >
> > > I have done many tests to try to determine the poor performance on my
> > > systems (FreeBSD-current connected directly to Windows XP via identical
> > > Intel Pro 1000 cards) and my only conclusion is that Samba on FreeBSD
> > > when talking to a Windows box is simply fubared. Im willing to bet thats
> > > not the case on Linux. I can get great speeds (~30MB/s) using ftp
> > > between the machines, but when i use Samba, i get a maximum of 11MB/s. I
> > > have tried playing with mtu size, samba options, polling, but there does
> > > not seem to be any visible bottlenecks, its just simply slow. It would
> > > be great if someone could get to the bottom of this, its quite
> > > frustrating.
> >
> > There are a number of TCP related configuration frobs on FreeBSD.  It
> > would be quite interesting to know how modifying each of the following
> > settings affects Samba performance:
> >
> > net.inet.tcp.delayed_ack
> > net.inet.tcp.sack.enable
> > net.inet.tcp.inflight.enable
> >
> > There has been recent evidence that the inflight bandwidth calculation is
> > having problems generating stable performance at high bandwidth and low
> > latency, so I might try that one first.
> >
> > Robert N M Watson
>
> I just tested on my home machine and delayed_ack and sack.enable have
> little or no effect on the results.
> inflight.enable on the other hand had a huge impact! With the file
> cached I've gone from flat 5.5MB/s up to also flat 7.2MB/s
> It's an improvement but there is still a difference up to those
> theoretical 12.5MB/s on a 100mbit link
> --
> Joao Barros

I tested on my pet server at work and gone from 58% to 80% bandwith
usage during a cached read with net.inet.tcp.inflight.enable disabled.


--
Joao Barros