Slow write performance with Win 98 and Samba (fwd)

Scott Prather sprather at
Thu Jun 21 14:18:23 GMT 2001

There is a way to work around the delayed tcp ack problem.  Send a SMBkeepalive packet to the client whenever there is a short write to the server.  It is not a pretty fix, but it makes Windows happy and solves this problem (this assumes you cannot turn off delayed ack on the OS).

On Thu, Jun 21, 2001 at 08:46:17AM -0400, David Collier-Brown wrote:
>  Scott Prather wrote:
> > > I have seen this problem also.  98 sends the ~64k SMBwriteraw then the
> > > small SMBwrite packet when sending to NT also.  The problem seems to be
> > > in the delayed ack for that small packet.  98 will time out waiting for
> > > that ack (~300ms each) before sending any more data to the server.
> "Christopher R. Hertel" wrote:
> > I have heard of this.  When I was at Connectathon the Sun folk talked
> > about this problem.  I think their solution was to pre-send the ack to
> > keep Windows going.  I need a better understanding of the problem.  I
> > would particularly like to know what NT is doing to prevent this problem.
> 	One of my colleagues ran into that thgis years: I'll
> 	ask him if he can hunt the information back down...
> --dave
> -- 
> David Collier-Brown,           | Always do right. This will gratify 
> Performance & Engineering Team | some people and astonish the rest.
> Americas Customer Engineering  |                      -- Mark Twain
> (905) 415-2849                 | davecb at

Scott Prather
Software Engineer
AIX PC Interoperability
sprather at

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