Re: Network traffic performance drops when two domUs share the pipe.

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Mon, May 22, 2023 at 04:25:54AM +0000, Mathew, Cherry G.* wrote:
> Hi There,
> 
> I have an outbound pipe that can hit about 1MBps downstream on dom0 or a
> single pv domU.
> 
> When I run a hvm domU as well, the total bandwidth performance of both
> domUs combined drops to about 20-30% (I don't have exact numbers as I
> haven't figured out a way to measure this), and sometimes, I notice that
> the connections from one or the other domU gets dropped.
> 
> This is on NetBSD 10.0_BETA dom0 with a NetBSD 9.3 pv domU and a FreeBSD
> 13.1-RELEASE hvm domU.
> 
> I'm wondering if anyone else is seeing this behaviour.

1MBps doesn't look that big. I have several Xen servers with gigabit
connectivity, and multiple domUs and didn't notice such issues.

Do you have some kind of firewall running on the dom0 ?

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--