How to Enable RDMA Adapter on ESXi

Products

• VMware vSphere ESXi
• VMware vSphere ESXi 8.0

Issue/Introduction

• After installing the RDMA driver on an ESXi host, the RDMA adapter is not visible in the vCenter Server UI.
  
  
• When running the command: esxcli rdma device list, no devices are listed

Cause

Installing the drivers is not enough to enable RDMA on the adapter. The driver module must explicitly be initialise to switch on RDMA functionality.

Resolution

Follow these steps to enable RDMA on the ESXi host:

Step 1: SSH to ESXi Host

• Connect to the ESXi host using SSH with root credentials.

Step 2: Check if RDMA Driver is Loaded

• Run:

esxcli rdma device list


  If no devices are listed, the RDMA driver might not be loaded
  
  

Step 3: Verify and Load RDMA Driver Module

• List loaded kernel modules:

   

  vmkload_mod -l | grep -i irdma

• If not loaded, manually load the RDMA driver:

   

  vmkload_mod irdma

• Confirm it loaded:

   

  vmkload_mod -s irdma

Step 4: Enable RDMA and RoCE on the Adapters

    For Intel NICs (icen driver):

• Enable RDMA on ports 0 and 1:

   

  esxcli system module parameters set -m icen -p "RDMA=1,1"

• Enable RoCE on irdman module:

   

  esxcli system module parameters set -m irdman -p "ROCE=1,1"

Details:

• icen → Intel Ethernet devices (e.g., E810 series).

• RDMA=1,1 → Enables RDMA on NIC port0 and port1.

• irdman → Intel RDMA management driver.

• ROCE=1,1 → Enables RoCE (RDMA over Converged Ethernet) on two interfaces.

 For ESXi Hosts with 4 RDMA NICs:

• Enable RDMA and RoCE on all four ports:

   

  esxcli system module parameters set -m icen -p "RDMA=1,1,1,1"

  esxcli system module parameters set -m irdman -p "ROCE=1,1,1,1"

Note:
Each number represents a physical port (port0, port1, port2, port3).
1 = enable; 0 = disable.

To Verify Current Settings:

esxcli system module parameters list -m icen

esxcli system module parameters list -m irdman

Step 5: Apply Specific Port Configurations

Scenario	Command
Enable RDMA/RoCE on vmnic0 & vmnic1; disable on vmnic2 & vmnic3	esxcli system module parameters set -m icen -p "RDMA=1,1,0,0" esxcli system module parameters set -m irdman -p "ROCE=1,1,0,0"
Enable RDMA/RoCE on vmnic2 & vmnic3; disable on vmnic0 & vmnic1	esxcli system module parameters set -m icen -p "RDMA=0,0,1,1" esxcli system module parameters set -m irdman -p "ROCE=0,0,1,1"
Disable RDMA/RoCE on all ports	esxcli system module parameters set -m icen -p "RDMA=0,0,0,0" esxcli system module parameters set -m irdman -p "ROCE=0,0,0,0"

 

Step 6: Reboot the Host

After applying the configuration changes, you must reboot the ESXi host for the settings to take effect.

 

Additional Notes:-

If the ESXi host has Broadcom RDMA adapters or Mellanox adapter , the driver module name will be different (e.g., bnxtnet or nmlx5 ), and name of the driver must adjust the commands accordingly.

Additional Information

If RDMA driver are installed and the modules are loaded the RDMA driver will be visible under ESXi-->Configure--->Networking tab