Limit NIC speed using “ethtool” in VMs

[Ertza]

Hi all, I noticed that the NICs we have access to are virtual functions (VFs) of the actual NIC, and I want to limit the bandwidth of my NIC using some tool, like ethtool. On my local setup I am able to do it with the following command:
ethtool -s ens27np0 autoneg off speed 10000 and I am able to limit the NIC to 10G, but on the Fabric VMs this does not seem to work. However for VFs, I think it can be done but at the hypervisor level using ip command like so:
ip link set ens27np0 vf 0 max_tx_rate 10000 min_tx_rate 10, where vf 0 is the virtual function number.

So, is there any way to limit my VM’s NIC myself, either by allocation of dedicated NIC to my project, or if there is some other command or way to do it? Or atleast can it be done for this time by you guys and then we can look for some other ways to do it later?

[Ilya Baldin]

This is something we need to look at – I would have expected it to work at least for dedicated NICs, maybe not SR-IOV. Can you use tc tool to limit the bandwidth?

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