Hi all, I am playing with HPC on openstack cloud deployment and I have a Mellanox infiniband nic card. I have a couple of deployment questions regarding the infiniband network. I am new to ib so excuse me if i ask noob questions. I have configured Mellanox for sriov and created a flavor with the property pci_passthrough:alias='mlx5-sriov-ib:1' to expose VF to my instance. so far so good and i am able to see the ib interface inside my vm and its active. (I am running SM inside infiniband HW switch) root@ib-vm:~# ethtool -i ibs5 driver: mlx5_core[ib_ipoib] version: 5.5-1.0.3 firmware-version: 20.28.1002 (MT_0000000222) expansion-rom-version: bus-info: 0000:00:05.0 supports-statistics: yes supports-test: yes supports-eeprom-access: no supports-register-dump: no supports-priv-flags: yes I didn't configure any ipaddr on the ibs5 interface etc. For testing purposes I have compiled mpirun hello world program to POC my infiniband network between two instances and I am able to successfully run the mpi sample program. Somewhere i read about neutron-mellanox agent to setup IPoIB for segmentation etc but not very sure that how complex it and what are the advantage here over just using simple passthru of SR-IOV Is this the correct way to set up an HPC cluster using openstack or is there a better way to design HPC on openstack?