On 12:14 Mon 12 Nov , Hal Rosenstock wrote: > On Mon, 2007-11-12 at 22:21 +0200, Sasha Khapyorsky wrote: > > Hi, > > > > On 19:13 Mon 12 Nov , Bernd Schubert wrote: > > > > > > so far we always did run opensm without the --lmc option, but just > > > recently I > > > read in opensm's manpage about it. > > > > > > <opensm manpage> > > > This option specifies the subnet's LMC value. The number of LIDs > > > assigned to > > > each port is 2^LMC. > > > The LMC value must be in the range 0-7. LMC values > 0 allow multiple > > > paths > > > between ports. LMC values > 0 should only be used if the subnet topology > > > actually provides multiple paths between ports, i.e. multiple > > > interconnects between switches. Without -l, OpenSM defaults to LMC = > > > 0, > > > which allows one path between any two ports. > > > </opensm manpage> > > > > > > In one of our configurations we do have a mts2400 (master) switch and > > > connected to it are two mts14400 switches (each with 3 connections to the > > > the > > > mts2400). > > > I think from the description of the opensm manpage we need to give the > > > "--lmc" > > > to make use of the 3 connections from each mts14400 switch to the mts2400 > > > switch, don't we? > > > > In theory (AFAIR by default OpenSM will not assign LMC for Switch port 0 > > Non 0 LMC is only valid (per spec) for enhanced SP0. LMC must be 0 for > base SP0.
Of course, this is too. But also it doesn't work for enhanced SP0 with current switches. Sasha > > due to some chip bug), when target is switch itself. But if you have > > end nodes connected to this switch and targets are end nodes when OpenSM > > will try to use all links for it. > > > > > Furthermore, from manpage I would think we even need this > > > option for proper inter-communication between the switch modules? > > > > For switch modules yes, but again OpenSM will not assign LMC for > > switches (even then --lmc specified), only for end nodes. In order to > > enable it you will need to turn on 'lmc_esp0' option in OpenSM options > > file. But as far as I remember it is not supported by switches now. > > It didn't work last time I tried it and I don't think it's been fixed. > > -- Hal > > > Sasha > > _______________________________________________ > > general mailing list > > [email protected] > > http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general > > > > To unsubscribe, please visit > > http://openib.org/mailman/listinfo/openib-general _______________________________________________ general mailing list [email protected] http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
