Re: Performance Problems, probably network related

[Adi Kriegisch <adi@xxxxxxxxxxxxxxx>]

Dear Klaus,

> Hardware: 2 servers, hardware is more or less identical
> 
> Server 1: Ubuntu 20.04 (xen 4.11, Kernel 5.4, Linux Bridge)
> AMD EPYC 7702P 64-Core Processor
> BCM57416 10G NIC
> dom0 has 4 vCPUs
> 
> Server 2: VMware ESXi 7.0
> AMD EPYC 7543P 32-Core Processor
> BCM57414 NetXtreme-E 10Gb/25Gb
> 
> 
> VM: Ubuntu 20.04, 8vCPUs. Running Knot DNS name server. I am doing benchmark
> tests against a VM running either on XEN or VMware.
> 
> In both cases no tuning (no cpu pinning ...).
> 
> The XEN VM: 170.000 qps
> The ESX VM: 575.000 qps
> 
> So, the XEN VM is much slower than the VMware VM. I thought this is because
> the XEN VM is "good old" PV. So I repeated the test with type=pvh but the
> results were the same. I did some more tests: When I test with a name
> server which is CPU intensive, then VMware is only a bit faster. But if the
> workload is more network-heavy (pps), then VMware is much more faster.
I do run similar setups, although with different NICs. From what I have
observed so far is that different offloading settings and different
drivers do often make a huge difference. (it might also be the case that
default settings are better optimized for heavy tcp traffic...)
Do you get huge differences when running iperf benchmarks on those
boxes?

all the best,
        Adi

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