Does anyone know, or is there documentation describing Windows timeout values for Read and Write via SMB?

Volker Lendecke Volker.Lendecke at SerNet.DE
Sun Dec 2 09:27:44 MST 2012

On Sun, Dec 02, 2012 at 07:11:24AM -0800, Richard Sharpe wrote:
> On Sat, Dec 1, 2012 at 9:54 PM, Christopher R. Hertel <crh at> wrote:
> > On 12/01/2012 11:30 PM, Jeremy Allison wrote:
> >> On Sat, Dec 01, 2012 at 01:56:57PM -0800, Richard Sharpe wrote:
> >>> Hi folks,
> >>>
> >>> Is there any documentation or any experience on how many SMBecho's
> >>> Windows is prepared to receive before it declares a READ or WRITE has
> >>> failed?
> >>
> >> Isn't it a timing thing rather than a "number of echos" thing ?
> >
> > Richard:  Are you talking about Windows clients sending SMBechos to see if
> > the server is alive or the server receiving and responding to SMBechos while
> > still processing other operations?
> Well, yes.
> More specifically, I am interested in knowing:
> 1. How much patience does Windows have? Ie. what are the timeout values?
> 2. Where are they defined in the registry?

We have done quite a bit of research here, but have not
found a definite answer. The problem is that you don't only
want to look at the Windows redirector, it is also
applications that might run into timeouts at a higher level.
Talks on the SDC floor track gave a timeout value of 25
seconds as the maximum for any request. It might also be
possible that you find timeouts in the SMB3 CA share
requirements in the SMB3 and FSA documents.


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