mlxconfig set fails with "-E- Parameter ' value is smaller than minimum allowed 1"

Hi Mellanox community,

I have problems setting the NUM_OF_VFS on my ConnectX-4 Ethernet adapter (MCX416A-BCAT).

I want to use mlxconfig to set NUM_OF_VFS, but regardless if I try it under ESXi 6.5 (mft-4.8.0.26-10EM-650.0.0.4598673.x86_64.vib) or Windows Server 2016 (WinMFT_x64_4_8_0_26.exe) I get the same error.

Here's what I'm trying (following HowTo Configure SR-IOV for ConnectX-4 with ESX 5.5/6.0 Native (Ethernet)):

[root@localhost:~] /opt/mellanox/bin/mlxconfig -d mt4115_pciconf0 set NUM_OF_VFS=8

Device #1:

----------

Device type:    ConnectX4

PCI device:     mt4115_pciconf0

Configurations:                              Next Boot       New

         NUM_OF_VFS                          4               8

Apply new Configuration? ? (y/n) [n] : y

Applying... Failed!

-E- Parameter ' value is smaller than minimum allowed 1

[root@localhost:~]

I would be happy if anybody could comment or try the same on his/her ESXi/Windows machines.

The funny thing is that I once managed to set SRIOV_EN to true and NUM_OF_VFS to 4, but I don't remember how I did that.

Thank you and best regards

Axel