[ofa-general] opensm: Unsupported attribute = 0xFF02

[Jason Gunthorpe]

On Thu, Nov 01, 2007 at 02:24:10AM +0200, Sasha Khapyorsky wrote:

> What are the reasons? I think complaint SMs should be able to
> inter-operate, of course not in part of proprietary extensions. At least
> I am able to run OpenSM with Voltaire SM on one subnet.

At a minimum how hand off is supposed to work is very vaugely
specified in the IBA.

Besides, even if hand off wasn't a problem the two SMs would have to
have very similar ideas on routing, multicast, QOS, services, etc or
the fabric will be badly disrupted after hand off.. Without extensions
to transfer this live data over before hand off it is unlikely to
be non-disruptive except in very constrained situations.

It seems to me the main benifit of the whole standardized mechanism
(in an interoperability context) is just to help make it so that a new
sm starting up doesn't just trash the fabric accidentally, and provide
at least some sensible behavior when two seperate subnets are combined
into one.

If you want to test hand over interop joining two operating networks
is a good way to do it - that is really hard to get right in all of
the cases :) This was the area where I felt the spec was weakest since
it really didn't say exactly when during the hand over exchanges each
SM was in control of the nodes, and exactly what should happen when
things go wrong was not specified..

Jason