Hello, I have two mahcines each having 3 live interfaces: lo, eth0 (interanet) and usb0 (internet). eth0 cannot access usb0 on the other machine (and vice-veras). Now, when I try to run the MPI program with these two hosts I cannot get any output, even --mca btl_base_verbose 30 does not give any output. If I set hostfile to have only localhost, then everything runs fine.
I tried out the same code and hostfile with two other machines with two interfaces: lo and eth1, which can access each other. The program runs fine on these machines. Next, I setup btl_tcp_if_exclude to lo,usb0 (on the first arch) and also the ip-address/mask, but this does not work either. When I run the program on one machine and do "ps aux | grep mpi" on the other I can see --hnp-uri being set to the usb0's ip-address, which it should not, because I have set usb0 to be exluded in the btl_tcp_if_exclude list. So, what exactly am I doing wrong here? I read the otimization FAQ and saw how openmpi builds the bipartite graphs for connection. But, as I said before, eth0 cannot access usb0's ip and vice-versa, how can I get rid of the usb0 ip-address showing up in --hnp-uri, because this is the only difference between the working and the non-working archs. Regards, -- Avinash Malik