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Subject: Re: [OMPI users] OpenMPI without IPoIB
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2009-12-01 19:55:15

You might also want to ensure that your Open MPI was built with
OpenFabrics support (i.e., to use verbs directly instead of IPoIB).
Try this:

    ompi_info | grep openib

If that returns a line with "openib" and "btl" in it, then your Open
MPI has OpenFabrics support (we named the plugin "openib" way back
when the OpenFabrics project was named "OpenIB" -- we stuck with the
name rather than updating it). If the output is empty, then your Open
MPI wasn't build with verbs/OpenFabrics support.

On Nov 25, 2009, at 1:03 PM, Don Kerr wrote:

> On 11/25/09 02:04, Vivek Satpute wrote:
>> Hi,
>> I tried to execute OpenMPI examples from OFED-1.4 stack and found
>> that all those
>> examples uses IPoIB.
> How are you determining that it is using IPoIB?
>> Is there any way to execute MPI applications on only Infiniband
>> stack i.e. without
>> using IPoIB module ?
>> Can we execute MPI applications using libibverbs, librdma, or some
>> other libraries ?
> OpenMPI by default will select and use the best available path. If
> the ibverbs interace is available and operational OpenMPI will use
> this for off-node MPI communication. If you are concerned that
> ibverbs is not in use specifically calling it out on the mpirun
> command line will assure you that it is being used, e.g. "mpirun --
> mca btl self,sm,openib .... ". This command will instruct OpenMPI to
> use shared memory for on node communication and openib (ibverbs),
> for off-node communication.
> -DON
>> Thanks,
>> Vivek
>> _______________________________________________
>> users mailing list
>> users_at_[hidden]
> _______________________________________________
> users mailing list
> users_at_[hidden]

Jeff Squyres