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how can we run linpack on Azure ?

    Question

  • hi -- we are following this (with 4 mediums):

    http://technet.microsoft.com/en-us/library/hh184316(WS.10).aspx#BKMK_mpiInSky

    and we get this:

    MPIDI_CH3I_Sock_connect(304)...: [ch3:sock] rank 6 unable to connect to rank 4 using business card <port=49252 description="10.28.218.224 RD00155D3247EF " shm_host=RD00155D3247EF shm_queue=2816:276 >
    MPIDU_Sock_post_connect(1124)..:
    save_valid_endpoints(1053).....: unable to connect to 10.28.218.224 RD00155D3247EF  on port 49252, no endpoint matches the netmask 192.168.0.0/255.255.255.0
    save_valid_endpoints(1071).....: gethostbyname failed, No such host is known.  (errno 11001)


    Saturday, May 07, 2011 12:07 PM

All replies

  • This looks like a netmask mismatch error. The netmask is used by the MPI processes to limit what hosts they are willing to receive packets from. To fix this, you need to look at the addresses and open up the netmask so that it will let in the traffic from your other MPI ranks.

    You can change the CCP_MPI_NETMASK cluster environment variable to match your Azure nodes. This requires administrator credentials on the cluster. For example:

    cluscf setenvs CCP_MPI_NETMASK=10.28.0.0/255.255.0.0

    Or, you can override the default netmask with an mpiexec argument. No admin credentials required. For example:

    mpiexec -env MPICH_NETMASK 10.28.0.0/255.255.0.0


    Note: The linpack on Azure guide now includes a step to check the netmask settings.
    • Proposed as answer by AliceLaura Thursday, May 12, 2011 9:20 PM
    Monday, May 09, 2011 4:31 PM