9.7.5. NFS over RDMA

NFS over Remote Direct Memory Access (NFSoRDMA) is best suited for CPU-intensive workloads where a large amount of data needs to be transferred. NFSoRDMA is usually used over an InfiniBand fiber, which provides higher performance with lower latency. The data movement offload feature available with RDMA reduces the amount of data copied around.

Procedure 9.2. Enabling RDMA transport in the NFS server

  1. Ensure the RDMA RPM is installed and the RDMA service is enabled:
    # yum install rdma; chkconfig --level 2345 rdma on
  2. Ensure the package that provides the nfs-rdma service is installed and the service is enabled:
    # yum install rdma; chkconfig --level 345 nfs-rdma on
  3. Ensure that the RDMA port is set to the preferred port (default for Red Hat Enterprise Linux 6 is 2050): edit the /etc/rdma/rdma.conf file to set NFSoRDMA_LOAD=yes and NFSoRDMA_PORT to the desired port.
  4. Set up the exported file system as normal for NFS mounts.

Procedure 9.3. Enabling RDMA from the client

  1. Ensure the RDMA RPM is installed and the RDMA service is enabled:
    # yum install rdma; chkconfig --level 2345 rdma on
  2. Mount the NFS exported partition using the RDMA option on the mount call. The port option can optionally be added to the call.
    # mount -t nfs -o rdma,port=port_number
The following Red Hat Knowledgebase article provides on overview of cards that use kernel modules supported for NFSoRDMA: What RDMA hardware is supported in Red Hat Enterprise Linux?