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Re: scp/ssh between two cygwin installations very slow


Christopher Faylor wrote:
On Mon, Apr 25, 2005 at 09:45:56PM +0200, Bernhard Ege wrote:

Bernhard Ege wrote:

I am trying to copy an 800MB file from my pc to my laptop. The pc has cygwin and cygwins sshd running and from the laptop I use the scp command to copy the file.

Result: 190kB/s with low (1-5%) cpu usage on both machines.

Expected result: at least 2-3MBps with somewhat higher cpuusage on both machines.

Doh. I completely forgot that in my .ssh/config I had ssh call a script using the ProxyCommand. That command is a shell script that detects which network I am connected to (company or my own) and uses a tunneling ssh command to the destination if on the company network or a direct connection using "connect" if on my own network.


The connect command is a fairly simple program that redirects stdin/stdout to a host:port. This way, I can either use a ssh to host:port if tunneling is required to connect to host:port if not.

The problem is that cygwin has a very low throughput using the script with the connect command. I guess it could be related to the slow pipe problem mentioned earlier (but was supposedly fixed).

I have tried without the ProxyCommand and the speed returned to an acceptable 1.5MBps.

I hope Cygwin can be fixed so the speed returns to normal :-)


Yep.  We'll get right on fixing that problem where fairly simple
programs which redirect stdin/stdout to a host:port cause reversions in
behavior of the "slow pipe" problem which was supposedly fixed.

It was either that kind of reply or some other reply indicating what additional info is required. Obviously I would submit the required information, but I don't know what would be relevant.


Anyway, here is the link to connect.c:

http://www.taiyo.co.jp/~gotoh/ssh/connect.html

And just create script like ssh-connect.sh:

#!/bin/bash
connect $1 $2

And in .ssh/config add the script to a destination:

ProxyCommand ssh-connect.sh %h %p


scp'in from the host which is reached through connect has its speed severely reduced.


It may be the problem with connect itself, but I am not sure how to test that.

Bernhard

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