[ofa-general] OpenSM "Dead end on path to LID" -- problem with updn, fixed with minhop

[Sasha Khapyorsky]

Hi Nathan,

On 10:57 Wed 23 Jul     , Nathan Dauchy wrote:
> 
> Given the network topology I described previously, how is "minhop"
> expected to behave differently than "updn"?

Up/Down guarantees credit loops free routing. In some topologies it drop
some connection which "violates" the rule, it may depend on how root
switches were detected, etc..

> Unless you recommend otherwise, I now hope to add back in the missing
> features and make sure everything is still OK:
> 	LMC=2
> 	MAXSMPS=4
> 	TIMEOUT=600
> 	12X links on subtree C.
> 
> 
> >
> > Also, where does the opensm run?
> > 
> 
> For the record, the SM host is connected to one of the "Subtree B" edge
> switches.  Hardware is an 8-core Intel Xeon 5450 @ 3.00GHz with 16GB
> RAM, and a single-port DDR "MT25204" HCA.  Software is CentOS-5.1,
> linux-2.6.18-53.1.21.el5, and OFED-1.3.1.
> 
> 
> Please let me know if there is additional diagnostic information I can
> gather in order to create a test case for future improvements to the
> "updn" routing engine.

Could you send us output of ibnetdiscover? And indicate GUID of host
where OpenSM is running?

Also full OpenSM log could be useful, likely "unknown remote side"
problem was unrelated to what you saw, but anyway it would be good to
look at how it was resolved.

Sasha