SCP protocol question and outstanding requests in SFTP

Chris Rapier rapier at
Sat Oct 13 04:01:13 EST 2007

William Ahern wrote:

> I had a similar problem, but in this case necessity demanded that scp be
> thrown out entirely. Instead, I wrote a wrapper script which _looked_ like
> scp, and worked like scp, but instead used sftp.
> The users never knew the difference. They weren't using esoteric features of
> scp, which most people don't. Most people use scp because it looks and feels
> like the cp(1) command. That's easy enough to imitate.

I agree and I've discussed this in the past with people here. 
Unfortunately, there isn't much I can do other than try to persuade 
people because we have no administrative control over the machiens they 
use to connect to us. If someone at say NCAR or SDSC or UIUC wants to 
transfer data to or from our machines they'll likely be using boxes 
administered by NCAR, SDSC or UIUC rather than a PSC box. So its simply 
impossible to impose the proper solution on them. All I can do is try to 
persuade them. How effective that is generally depends on the ability 
and local authority of the user. So while I've been able to get HPN-SSH 
to be a required component for Grid data transfer nodes I can't get Joe 
Admin at some lab to make sure his users make the best use of them.

> There's a great degree of overlap between people who stubbornly refuse to
> use another tool, and those who use the tool in a most basic,
> straight-forward fashion.

Exactly, but in my experience this tends to be the majority of the 
users. Or at least the users who have the ability to raise the biggest 
stink. Since we are dependent on external funding for our operations 
annoying these people tends to be a suboptimal solution for us.

> It's not fair (and I suspect this method of
> arguing is common, though I am not pointing fingers by any means), to hold
> up the great body of scp users to persuade why scp is important, but then
> dismiss alternatives because the alternatives don't meet the demands of a
> much smaller sub-group. Very likely the majority can be transparently
> migrated, more-or-less.

Indeed. Except for those that can't and if this is more than some very 
small number of people it can end up being disastrous.

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