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

[Sasha Khapyorsky]

On 20:41 Wed 31 Oct     , Jason Gunthorpe wrote:
> 
> 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.

It is at least basically described in the IBA - with exchanging SMInfo.

> 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

In worst case the routing tables and QoS setups could be reconfigured
from scratch (just as if it could be first SM run), and all SA related
things could be rerequested with ClientReregistration bit.

And sure, some configurations (partitions, QoS, routing, etc.) can be
not synchronized for SMs, but then the differences in a fabric setups
should be expected results.

And I'm not about "how fast and efficient it is" and even not about
"interoperability" bugs in various implementations.

> 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..

Ok, so we are not about "impossibility" to do this... Just current lack
of standardization makes it hard to do handover properly?

Sasha