3.6 RDMA Issues

The following issues are noted for RDMA:

  • ibacm service is disabled by default.  The ibacm service is disabled by default immediately after installation. This means that the ibacm service does not automatically start after a reboot. You must enable the service if you wish this service to start after reboot:

    # systemctl enable ibacm

    (Bug ID 28074471)

  • Issues when Network Manager control is enabled or disabled.  Several issues have been observed when the NM_CONTROLLED=yes is set for an interface that is used for RDMA. For these reasons, Oracle recommends setting NM_CONTROLLED=no in the interface configuration, however when Network Manager control is disabled, the CONNECTED_MODE=yes parameter is ignored for InfiniBand interfaces. It is possible to work around this issue by setting the connected mode manually by running the following command:

    # echo connected > /sys/class/net/ib0/mode

    where ib0 is the interface that you wish to change mode for. You may need to run this command after a reboot. (Bug ID 28074921)

  • Error, some other host already uses address xxx.xxx.xxx.xxx The following error message might be triggered in certain instances:

    Error, some other host already uses address  xxx.xxx.xxx.xxx

    The following are the two instances in which this error message might be triggered:

    • When active-bonding is enabled, and you run the ifup ib-interface command.

    • When you run the systemctl start rdma command.

    You can ignore this message, as in both cases, the InfiniBand interface is brought up successfully. (Bug ID 28097516)

  • Unloading resilient_rdmaip can result in issues accessing InfiniBand interfaces.  Unloading the resilient_rdmaip module can cause issues accessing and configuring InfiniBand interfaces. Attempts to use the ifconfig command on an InfiniBand interface after the module has been unloaded, results in a 'Device not found' message, and no IP information for these interfaces is available. The interfaces need to be re-initialized with the ifup command. The active bonding feature is unaffected by this issue. (Bug ID 28123680)