On Sat, 04 May 2013 08:00:53 -0700
Geoff Nordli <geo...@gnaa.net> wrote:
> On 13-05-04 02:35 AM, Stephan von Krawczynski wrote:
> > Sorry guys, but I cannot let go this topic.
> > Maybe it helps to understand the reason why I am very interested in a
> > solution:
> >
> > Imagine you have two guests, one server of some network file system and one
> > client for it.
> > If the client file-stats some 10.000 files (which creates small single
> > packets
> > for every file) there is a big difference between having latencies around
> > 0.100 ms and 10-100 ms (which is quite a normal value while using
> > virtio-net).
> > So bandwidth does not help you a lot here.
> > If anybody has an idea what to patch on the OSE virtio-net driver feel free
> > to
> > make suggestions.
> > If even the devs are not interested in this topic I'll probably end up with
> > qemu, because this question is a real show-stopper.
> >
>
> there is definitely something not right there.
>
> Have you tried other network drivers? How about the Intel drivers?
>
> As well, are you doing host-only or bridged network configuration?
>
> For example, I just spun up two Ubuntu 12.04 guests using the Intel 1000
> MT (82540EM) driver on the host-only network with this output.
>
> --- 10.10.64.101 ping statistics ---
> 82 packets transmitted, 82 received, 0% packet loss, time 81110ms
> rtt min/avg/max/mdev = 0.294/0.921/1.562/0.176 ms
>
>
>
> Geoff
Ah, thanks Geoff, someone to talk to :-)
Well, I did try all kinds of setups. The basic setup is openSUSE 12.3, kernel
is 3.8.11, vbox is 4.2.12.
In terms of network I am generally talking about bridged mode.
Regarding drivers I tried:
PCNet PCI-II : works, but bad performance, around 150 MBits/s between two
guests
PCNet FAST III: exactly like above, no real wonder as this is the same
driver on guest
Intel Desktop e1000 MT: works, the performance is around 400-500 MBit/s
Intel Server Adapters: all broken, I can shoot them down with iperf in a minute
the guests network goes offline as if all cables were
disconnected
All these have in common that the latency looks quite like physical, around
0.150-0.300 ms.
virtio-net: works, the performance is around 800-900 MBits/s, but the latency
hops around from 0.000ms to 800-900 ms (no kidding) _during the same ping
command_. Almost every ping has completely different times.
All tested with guest kernels 3.2.44 and 3.4.42. There seems to be no
difference between them.
The host does not swap btw and iperfs above 940 MBits/s on its physical
network.
Maybe things are related to some timer or scheduler configuration in the hosts
kernel setup, I don't know. I have not found any hints about how to configure
a kernel best for virtualbox both host and guest.
--
Regards,
Stephan
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