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Subject: Re: [OMPI devel] RFC - "system-wide-only" MCA parameters
From: Nadia Derbey (Nadia.Derbey_at_[hidden])
Date: 2009-09-04 09:59:13


On Fri, 2009-09-04 at 07:50 -0600, Ralph Castain wrote:
> Let me point out the obvious since this has plagued us at LANL with
> regard to this concept. If a user wants to do something different, all
> they have to do is download and build their own copy of OMPI.
>
> Amazingly enough, that is exactly what they do. When we build our
> production versions, we actually "no-build" modules we don't want them
> using (e.g., certain BTL's that use privileged network interfaces) so
> even MCA params won't let them do something undesirable.
>
> No good - they just try until they realize it won't work, then
> download and build their own version...and merrily hose the system.
>
> My point here: this concept can help, but it should in no way be
> viewed as a solution to the problem you are trying to solve. It is at
> best a minor obstacle as we made it very simple for a user to
> circumvent such measures.
>
> Which is why I never made the effort to actually implement what was in
> that ticket. It was decided that it really wouldn't help us here, and
> would only result in further encouraging user-owned builds.

Ralph,

Let's forget those people who intentionally do bad things: it's true
that they will always find a way to bypass whatever has been done...

We are not talking about security here, but there are client sites where
people do not want to care about some mca params values and where those
system-wide params should not be *unintentionally* set to different
values.

Regards,
Nadia

>
> :-(
>
>
> On Sep 4, 2009, at 12:42 AM, Jeff Squyres wrote:
>
> > On Sep 4, 2009, at 8:26 AM, Nadia Derbey wrote:
> >
> >> > Can the file name ( openmpi-priv-mca-params.conf ) also be
> >> configurable ?
> >>
> >> No, it isn't, presently, but this can be changed if needed.
> >>
> >
> >
> > If it's configurable, it must be configurable at configure time --
> > not run time -- otherwise, a user could just give a different
> > filename at runtime and get around all the "privileged" values.
> >
> > --
> > Jeff Squyres
> > jsquyres_at_[hidden]
> >
> > _______________________________________________
> > devel mailing list
> > devel_at_[hidden]
> > http://www.open-mpi.org/mailman/listinfo.cgi/devel
>
> _______________________________________________
> devel mailing list
> devel_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/devel
>

-- 
Nadia Derbey <Nadia.Derbey_at_[hidden]>