Should I turn off TSO and GSO on vmbr0?

[Lonnie]

In Proxmox 5.1-41, after switching a Windows 2012 VM's Network Device from E1000 to VirtIO (and installing the latest stable VirtIO drivers), I've had users of physical workstations (that use a client/server application hosted by this virtual machine) say that application performance has been degraded.

I've been reading a lot of articles that suggest using ethtool to turn off TSO and GSO on vmbr0. The idea seems to be, that since vmbr0 is not actually a physical network card, offloading work to it ultimately makes the server do double the work and ultimately (due to bugs) causes packet loss; so it is best to just let the VM's OS do that work instead. For example, this one article sites a few sources suggesting this:

http://kris.io/2015/10/01/kvm-network-performance-tso-and-gso-turn-it-off/

Is this still advisable in Proxmox 5.1-41?

 

[wolfgang]

Hi,

Hardware offloading dependence on the used HW .
I never had problems with Intel NICs but always with Realtek.
So it is more a question of the used driver.

 

[tjh]

Dragging up an old thread here, but there's this post on reddit yesterday that said his performance improved once he disabled hardware offload on the interfaces on the virtual bridges.

I just wish I could find some concrete evidence either way about this, so far it's all "well I tried X and it worked" type posts, nothing that explains if these things really make a difference or not (and if they do, why they do)