On Nov 3, 2011, at 2:55 PM, Blosch, Edwin L wrote: > I might be missing something here. Is there a side-effect or performance loss > if you don't use the sm btl? Why would it exist if there is a wholly > equivalent alternative? What happens to traffic that is intended for another > process on the same node?
There is a definite performance impact, and we wouldn't recommend doing what Eugene suggested if you care about performance. The correct solution here is get your sys admin to make /tmp local. Making /tmp NFS mounted across multiple nodes is a major "faux pas" in the Linux world - it should never be done, for the reasons stated by Jeff. > > Thanks > > > -----Original Message----- > From: users-boun...@open-mpi.org [mailto:users-boun...@open-mpi.org] On > Behalf Of Eugene Loh > Sent: Thursday, November 03, 2011 1:23 PM > To: us...@open-mpi.org > Subject: Re: [OMPI users] EXTERNAL: Re: How to set up state-less node /tmp > for OpenMPI usage > > Right. Actually "--mca btl ^sm". (Was missing "btl".) > > On 11/3/2011 11:19 AM, Blosch, Edwin L wrote: >> I don't tell OpenMPI what BTLs to use. The default uses sm and puts a >> session file on /tmp, which is NFS-mounted and thus not a good choice. >> >> Are you suggesting something like --mca ^sm? >> >> >> -----Original Message----- >> From: users-boun...@open-mpi.org [mailto:users-boun...@open-mpi.org] On >> Behalf Of Eugene Loh >> Sent: Thursday, November 03, 2011 12:54 PM >> To: us...@open-mpi.org >> Subject: Re: [OMPI users] EXTERNAL: Re: How to set up state-less node /tmp >> for OpenMPI usage >> >> I've not been following closely. Why must one use shared-memory >> communications? How about using other BTLs in a "loopback" fashion? >> _______________________________________________ >> users mailing list >> us...@open-mpi.org >> http://www.open-mpi.org/mailman/listinfo.cgi/users >> _______________________________________________ >> users mailing list >> us...@open-mpi.org >> http://www.open-mpi.org/mailman/listinfo.cgi/users > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users