To Whom It May Concern, Recently, I switched to CH4 device in MPICH 3.3.1 for better network performance over the RoCE network we are using. I realized that my code fails to run when I use direct interface of OrangeFS 2.9.7. It exits without any error. But even simple helloworld cannot print anything. It happens only when I enable direct interface of OrangeFS by linking -lorangefsposix. Could you please help me on this issue? Here are some information that might be useful: Output of ibv_devinfo of 40Gbps Mellanox ConnectX-4 Lx adapter: hca_id: mlx5_0 transport: InfiniBand (0) fw_ver: 14.20.1030 node_guid: 248a:0703:0015:a800 sys_image_guid: 248a:0703:0015:a800 vendor_id: 0x02c9 vendor_part_id: 4117 hw_ver: 0x0 board_id: LNV2430110027 phys_port_cnt: 1 port: 1 state: PORT_ACTIVE (4) max_mtu: 4096 (5) active_mtu: 1024 (3) sm_lid: 0 port_lid: 0 port_lmc: 0x00 link_layer: Ethernet hca_id: i40iw0 transport: iWARP (1) fw_ver: 0.2 node_guid: 7cd3:0aef:3da0:0000 sys_image_guid: 7cd3:0aef:3da0:0000 vendor_id: 0x8086 vendor_part_id: 14289 hw_ver: 0x0 board_id: I40IW Board ID phys_port_cnt: 1 port: 1 state: PORT_ACTIVE (4) max_mtu: 4096 (5) active_mtu: 1024 (3) sm_lid: 0 port_lid: 1 port_lmc: 0x00 link_layer: Ethernet MPICH 3.3.1 configuration command: ./configure --with-device=ch4:ofi --with-pvfs2=/home/kfeng/install --enable-shared --enable-romio --with-file-system=ufs+pvfs2+zoidfs --enable-fortran=no --with-libfabric=/home/kfeng/install OrangeFS 2.9.7 configuration command: ./configure --prefix=/home/kfeng/install --enable-shared --enable-jni --with-jdk=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.191.b12-0.el7_5.x86_64 --with-kernel=/usr/src/kernels/3.10.0-862.el7.x86_64 Make command: mpicc -o ~/hello ~/hello.c -L/home/kfeng/install/lib -lorangefsposix The verbose outputs of mpiexec are attached. Thanks Kun