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Re: very poor cygwin scp performance in some situations

----- Original Message ----- From: "Corinna Vinschen"
On Mar 27 16:39, Steven Hartland wrote:
I've done quite a bit of digging and not found any real answers
on why cygwin's scp performance is so poor.

Cygwin is just emulating POSIX by calling Windows functions. It's not an operating system which runs natively on the machine, so what do you expect? If you're unhappy with scp's performance you can try using:

- sftp

- tar over ssh:

tar cf - dir-to-copy | ssh remotemachine 'cd targetdir && tar xf -'


Sorry to sound rude but did you even look at the figures I posted?

From them I think its fair to say there is nothing to stop cygwin
performing quite well in all ssh / scp operations but as it stands there
are a number of issues; specifically copying off a cygwin machine
from a remote box which atm produces only 700KB/s.

The transfer the other way round obtains over 6MB/s which is pretty
good although could still possibly see some gains.

Always willing to trying things here's the results from your suggestions:
sftp provides a small improvement 1.1MB/s
tar + ssh is the same as scp 700KB/s
I'd already tried hpn but although it compiles fine just instantly
disconnects so is unfortunately a none starter.

I'm not sure what everyone uses cygwin for but I would be surprised
if a large amount of people dont use if for interaction with existing
unix systems and as such make heavy use of facilities such as ssh and
scp on a daily basis so any work on this would be highly beneficial.

I'm quite willing, as hopefully I've show, to put in some ground leg
work to try and find a solution to this one but due to my lack of
experience both with the core of cygwin and with ssh / scp without
some pointers Im not going to make much progress.


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