Hi, Which version of MPICH2 are you using? Did you try the "sock" channel (See if it works)? (PS: We haven't tested MPICH2 on Windows with ec2 instances.) Regards, Jayesh ----- Original Message ----- From: "Nicholas Sgro" <[email protected]> To: [email protected] Sent: Thursday, February 7, 2013 11:29:57 AM Subject: [mpich-discuss] Amazon ec2 Windows machine Hi all, I am trying to run the example cpi.exe across 2 amazon ec2 instances running windows. I have different problems depending on the channel I choose. If I try nemesis, I get the following error: Fatal error in MPI_Init: Other MPI error, error stack: MPIR_Init_thread(392).................: MPID_Init(139)........................: channel initialization failed MPIDI_CH3_Init(38)....................: MPID_nem_init(196)....................: MPIDI_CH3I_Seg_commit(366)............: MPIU_SHMW_Hnd_deserialize(324)........: MPIU_SHMW_Seg_open(863)...............: MPIU_SHMW_Seg_create_attach_templ(763): unable to allocate shared memory - OpenFileMapping The system cannot find the file specified. If I try to use shm, cpi.exe uses 100% of the processors on both machines, but makes no progress and I have to cancel the job. I am attaching logs from smpd from both machines from the runs with nemesis and shm. I don't have any experience with mpich, so I have no idea what the problem is. Any guidance would be appreciated. Thanks _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss