Re: Network Performance?

[Jordan Geoghegan <jgeoghegan60 at gmail dot com>]

Thanks for testing that for me! I had feared I was having filesytem 
speed issues as seen in WSL, but alas I was wrong. It turns out my issue 
with network performance bottnecks is due to the TCP window size not 
adjusting. Looking at the debug output of ssh, it seems the window size 
adjusts aren't being performed. Strangely enough, when I grabbed a fresh 
machine to test Cygwin on, I am able to get near wire speeds. Very strange.


On 04/08/18 16:08, L A Walsh wrote:
> Jordan Geoghegan wrote:
> > Thanks for the info. Would you be able to test file performance over 
> > the network? If you could just try copying a ~1GB file or what have 
> > you via sftp or rsync with actual writes to disk, I would be very 
> > interested to see how the numbers change.
> ---
>     Here is scp and rsync, using a tar, and a 1g file filled
> with zeros.   Note, my env RSYNC_RSH=ssh
>
> > time scp default-nlaw.tar.7z ishtar:/tmp 
> default-nlaw.tar.7z                           100%   62MB 83.1MB/s   
> 00:00    0.91sec 0.04usr 0.01sys (6.65% cpu)
> > ssh ishtar rm /tmp/default-nlaw.tar.7z
> > time rsync -v default-nlaw.tar.7z ishtar:/tmp/
> default-nlaw.tar.7z
> sent 64,588,267 bytes  received 35 bytes  43,058,868.00 bytes/sec
> total size is 64,572,413  speedup is 1.00
> 0.73sec 0.37usr 0.17sys (74.32% cpu)
> time scp /tmp/1g ishtar:/tmp/ 
> 1g                                            100% 1014MB 72.3MB/s   
> 00:14    15.00sec 0.04usr 0.07sys (0.81% cpu)
> > time rsync -v /tmp/1g ishtar:/tmp/
> 1g
> sent 1,063,515,721 bytes  received 35 bytes  125,119,500.71 bytes/sec
> total size is 1,063,256,064  speedup is 1.00
> 7.57sec 5.95usr 3.40sys (123.54% cpu)
>
> > uname -a
> CYGWIN_NT-6.1 Athenae 2.10.0(0.325/5/3) 2018-02-02 15:16 x86_64 Cygwin
>
>
> I generally don't use them to transfer files over a closed
> subnet as the performance is sub-optimal.
>
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