<div dir="ltr"><div dir="ltr"><div dir="ltr"><div>Hi Faraz</div><div><br></div><div>By all means, download the Open MPI tarball and build from source.</div><div>Otherwise there won't be support for IB (the CentOS Open MPI packages most likely rely only on TCP/IP).</div><div><br></div><div>Read their README file (it comes in the tarball), and take a careful look at their (excellent) FAQ:</div><div><a href="https://www.open-mpi.org/faq/">https://www.open-mpi.org/faq/</a></div><div>Many issues can be solved by just reading these two resources.</div><div><br></div><div>If you hit more trouble, subscribe to the Open MPI mailing list, and ask questions there, <br></div><div>because you will get advice directly from the Open MPI developers, and the fix will come easy.</div><div><a href="https://www.open-mpi.org/community/lists/ompi.php">https://www.open-mpi.org/community/lists/ompi.php</a><br></div><div><br></div><div>My two cents,</div><div>Gus Correa<br></div></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Apr 30, 2019 at 3:07 PM Faraz Hussain <<a href="mailto:info@feacluster.com">info@feacluster.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Thanks, yes I have installed those libraries. See below. Initially I  <br>
installed the libraries via yum. But then I tried installing the rpms  <br>
directly from Mellanox website (  <br>
MLNX_OFED_LINUX-4.5-1.0.1.0-rhel7.5-x86_64.tar ). Even after doing  <br>
that, I still got the same error with openmpi. I will try your  <br>
suggestion of building openmpi from source next!<br>
<br>
root@lustwzb34:/root # yum list | grep ibverbs<br>
libibverbs.x86_64                     41mlnx1-OFED.4.5.0.1.0.45101<br>
libibverbs-devel.x86_64               41mlnx1-OFED.4.5.0.1.0.45101<br>
libibverbs-devel-static.x86_64        41mlnx1-OFED.4.5.0.1.0.45101<br>
libibverbs-utils.x86_64               41mlnx1-OFED.4.5.0.1.0.45101<br>
libibverbs.i686                       17.2-3.el7              <br>
rhel-7-server-rpms<br>
libibverbs-devel.i686                 1.2.1-1.el7             <br>
rhel-7-server-rpms<br>
<br>
root@lustwzb34:/root # lsmod | grep ib<br>
ib_ucm                 22602  0<br>
ib_ipoib              168425  0<br>
ib_cm                  53141  3 rdma_cm,ib_ucm,ib_ipoib<br>
ib_umad                22093  0<br>
mlx5_ib               339961  0<br>
ib_uverbs             121821  3 mlx5_ib,ib_ucm,rdma_ucm<br>
mlx5_core             919178  2 mlx5_ib,mlx5_fpga_tools<br>
mlx4_ib               211747  0<br>
ib_core               294554  10  <br>
rdma_cm,ib_cm,iw_cm,mlx4_ib,mlx5_ib,ib_ucm,ib_umad,ib_uverbs,rdma_ucm,ib_ipoib<br>
mlx4_core             360598  2 mlx4_en,mlx4_ib<br>
mlx_compat             29012  15  <br>
rdma_cm,ib_cm,iw_cm,mlx4_en,mlx4_ib,mlx5_ib,mlx5_fpga_tools,ib_ucm,ib_core,ib_umad,ib_uverbs,mlx4_core,mlx5_core,rdma_ucm,ib_ipoib<br>
devlink                42368  4 mlx4_en,mlx4_ib,mlx4_core,mlx5_core<br>
libcrc32c              12644  3 xfs,nf_nat,nf_conntrack<br>
root@lustwzb34:/root #<br>
<br>
<br>
<br>
> Did you install libibverbs  (and libibverbs-utils, for information and<br>
> troubleshooting)?<br>
<br>
> yum list |grep ibverbs<br>
<br>
> Are you loading the ib modules?<br>
<br>
> lsmod |grep ib<br>
<br>
</blockquote></div>