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Re: Bug in scp v3.0.1


From: Brad Arlt <arlt () cpsc ucalgary ca>
Date: Wed, 31 Oct 2001 13:42:18 -0700

On Wed, Oct 31, 2001 at 12:18:47AM -0500, Jonathan A. Zdziarski wrote:
I was scp'ing a 2MB file to my home computer over a DSL line and just
happened to run top at the same time.  I immediately noticed this line:

13864 root       1  30    0 2884K 1744K run     0:38 42.00% sshd2

It appears that scp'ing a file over a slow connection causes the process to
suck up a huge number of resources.  There's most likely no usleep()
somewhere it's needed.  A couple scp's over slow connections could severely
degrade the boxes performance.

This test was performed on a Solaris 8_x86 machine.

If you are refering to SSH Communication Security Inc's SSH2 v3.0.1,
this is a known bug, and they are working on the fix.

It affects all server implimentations (UNIX and Windows).  For
a list of all the known bugs check out:

http://www.ssh.com/faq/index.cfm?category=129

I get 99% utilization on a fast link (Cable modem, and 10/100/1000Mb
Ethernet.
----------------------------------------------------------------------------
   __o          Bradley Arlt      Email: arlt () cpsc ucalgary ca         o__
 _ \<_                              WWW: www.acs.ucalgary.ca/~bdarlt   _>/ _
(_)/(_)  -Eat well, sleep peacefully, drink lots, and ride like hell. (_)\(_)


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