Hoping someone can provide help as to what I am doing wrong or missing:

  • Have 3 test servers (hostnames node1..3) each with a Mellanox MT28908 family infiniband card, model CX653105A
  • Have Mellanox HDR infiniband switch QM8700.
  • On each server running RHEL 7.9, kernel 3.10.0-1160.49.1.el7.x86_64
  • Was referencing Access_Redhat Storage Admin Guide, 8.6 Configuring The NFS Server.
  • systemctl disable firewalld; service firewalld stop
  • selinux set to permissive in /etc/selinux/config.
  • Have MLNX_OFED_LINUX-5.4- (362Mb) downloaded from https://www.mellanox.com/products/infiniband-drivers/linux/mlnx_ofed; and installed on each node1, node2, node3.
    • mount -o loop MLNX_OFED_LINUX-5.4- /mlx;
    • run /mlx/mlnxofedinstall
    • let it do its thing, yes to all prompts, it uninstalls existing rhel ofed stuff that it says is incompatible.
    • chkconfig opensm on and openibd.service=enabled on all 3 nodes.
    • rebooted
  • configured network for ib0 via gui under System Tool-Settings-Network.
  • ib0 Transport Mode = DATAGRAM; MTU = automatic; ipv4 address manually set; ipv6=ignore.
  • manually edited /etc/hosts to add ip addresses of node1, node2, node3 of my 3 test servers: 172.16.2.{1,2,3}
  • This infiniband network is the only network physically cabled between these 3 servers and switch.
  • I can successfully ping and ssh or scp to each over the infiniband network.
  • /etc/sysconfig/nfs is the same on all nodes, that file listed below.
  • on node1 : /etc/exports : /scratch *(rw,async,no_root_squash) and nfs.service=enabled
  • node2 or node3 : mount node1:/scratch /scratch works
  • node2 or node3 : mount -o rdma,port=20049 node1:/scratch /scratch results in mount.nfs : mount system call failed
  • There is an /etc/rdma/mlx4.conf file, which I have not modified.
  • There is no /etc/rdma/rmda.conf but there is an /etc/rdma/modules/rdma.conf.
  • I did ln -s /etc/rdma/modules/rdma.conf /etc/rdma/rdma.conf; not sure if needed.
  • I uncommented all the lines (services) within; the syntax seems different there is no "LOAD="; can post this file if needed.
  • /var/log/messages after trying mount -o proto=rdma, not sure if this is significant: Request for unknown module key Mellanox Technologies signing key <40 hex chars> err -11

I have tried setting the Transport Protocol to Connected in System-Tools-Setting-Network on two nodes but then the Off/On becomes off and will not stay on, and an ip a shows ib0 link up but has no ip address and then there is no network connectivity between the two.


  1. to have NFS over RDMA, what should the Transport Mode be set to, DATAGRAM or CONNECTED ?
  2. For a basic TCP network over infiniband like I can get working, is what I described above correct? Did I miss anything of do anything wrong? Regarding opensm running on every server is that correct?
  3. Is mount -o rdma node1:/scratch /scratch all that is needed if everything else is configured properly to get NFS=RDMA working
  4. If/when NFS+RDMA is actually working, will a general tcp type network still exist between my little network that I can ssh or scp between them?
  5. A systemctl list-unit-files | grep nfs shows 13 different nfs-xxx.service's. Do any of these others (blkmap, config, idmap, lock, mountd, rquotad, server, lock) need to be enabled?
  6. Will selinux=enforcing be a problem?


My /etc/sysconfig/nfs  file on each server



1 Answer 1


what I have come to learn is that there seems to be an incompatibility between what the MLNX_OFED_LINUX-5.4- and systemctl rdma.service. When installing the MLNX iso, when it does its thing and installs everything it does, it removes & replaces the redhat version of rdma-core-22.4-6.el7_9.x86_64 with it's own, and as a result there is no longer an rdma.service.

Help from my redhat service ticket took me down the path of making sure rdma.service was enabled and running, which wasn't because I went down the path of the MLNX iso install.

I reinstalled RHEL 7.9 from dvd, choosing Infiniband Support package, and my infiniband network basically started working after the reboot... opensm was installed and running.

From there it was a matter of making sure /etc/rdma/rdma.conf has all the services as yes, especially SVCRDMA_LOAD. The TECH_PREVIEW_LOAD was left as no.

open port 2049 for nfs4, and 20049 for rdma in firewall.

edit /etc/sysconfig/nfs and only change


The mount command on an nfs-client is just

mount    -o rdma,port=20049    server:/scratch    /scratch

I also observed incompatibility and failed nfs mount outright between servers that used the MLNX iso to get infiniband working to those that used that did not and used the redhat infiniband packages. So it seems either use MLNX everywhere or not at all, I don't know. I will only be using the MLNX iso to allow firmware update on the installed inifiniband card and say no to everything else it wants to install. I think I came across some MLNX documentation saying it does things a little differently and that it uses openibd or something, but it proved to difficult to get working.

I was only ever able to get nfs v4.1 working; /etc/nfs.conf mentions nfs4.2 being available and redhat even has articles about how to enable it, which I was never successful with.

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