CentOS7.6にアップデートしたらOFEDがうまく動かなくなったので、他の方法でInfiniBandを動かそうと思います。

yum groupinstall "Infiniband Support"
yum install infiniband-diags

# ibstat
CA 'mlx4_0'
        CA type: MT26428
        Number of ports: 2
        Firmware version: 2.9.1000
        Hardware version: b0
        Node GUID: 0x0021280001fca108
        System image GUID: 0x0021280001fca10b
        Port 1:
                State: Active
                Physical state: LinkUp
                Rate: 40
                Base lid: 1
                LMC: 0
                SM lid: 1
                Capability mask: 0x0259086a
                Port GUID: 0x0021280001fca109
                Link layer: InfiniBand
        Port 2:
                State: Down
                Physical state: Polling
                Rate: 10
                Base lid: 0
                LMC: 0
                SM lid: 0
                Capability mask: 0x0259086a
                Port GUID: 0x0021280001fca10a
                Link layer: InfiniBand

GUIDを確認したらopensmに設定を追記します。

#vi /etc/sysconfig/opensm

以下を追記します。
GUIDS=”0x0021280001fca109 0x0021280001fca10a”

サービスを起動します。

#systemctl enable opensm.service
#systemctl start opensm.service
#systemctl status opensm.service
● opensm.service - Starts the OpenSM InfiniBand fabric Subnet Manager
   Loaded: loaded (/usr/lib/systemd/system/opensm.service; enabled; vendor preset: disabled)
   Active: active (running) since 日 2019-06-09 21:23:48 JST; 2min 24s ago
     Docs: man:opensm
  Process: 14266 ExecStart=/usr/libexec/opensm-launch (code=exited, status=0/SUCCESS)
   CGroup: /system.slice/opensm.service
           tq14268 /bin/bash /usr/libexec/opensm-launch
           tq14270 /usr/sbin/opensm -g 0x0021280001fca109 --subnet_prefix 0xf...
           tq14271 /bin/bash /usr/libexec/opensm-launch
           mq14272 /usr/sbin/opensm -g 0x0021280001fca10a --subnet_prefix 0xf...