Internally MPICH calls ‘gethostbyname’ in initialization. Looks like the function does not work on your B&C machines. — Huiwei On Aug 26, 2014, at 3:24 PM, James <jamesqf at charter.net> wrote: > Unexpected output in collparmt: MPID_nem_tcp_init(377).............: > gethostbyname failed, q2 (errno 1)