Re: Network with QEMU generated image (guix system vm)?

[ng0]

Aljosha Papsch <address@hidden> writes:

> On 26.09.2016 19:30, Jan Nieuwenhuizen wrote:
>> What I don't understand: sometimes the clone works instantly, sometimes
>> I need to "wait a bit" until cloning or `ping gitlab.com' works.  It
>> seemed to be always immediately available when I added the mcron and
>> rottlog test services, which confuses me even more.  Might just be
>> coincidence.
>>
>> Greetings,
>> Jan
>>
> I'm guessing here but it sounds alot like neighbor discovery being slow 
> with ARP. I had the same issue few months ago with GNS3 where I created 
> a virtual topology. They use qemu VMs for each host. After creating 
> topology I wanted to ping a little and some packages would be dropped 
> before they went through.
>
> http://wiki.qemu.org/Documentation/Networking suggests in section 
> "Network backend types" that user networking is slow while tap 
> networking is fast. So ARP discovery performance might just suffer from 
> qemu user networking. Maybe it's worth trying tap networking. I used it 
> a few weeks ago (with lxc containers) and it's pretty flexible. Haven't 
> paid attention to performance though.

Afaik gnunet uses tun/tap when available[0]. My limited knowledge about
qemu I assumed that those modules in the way I can configure guix so far
do not exist in the way I might want them in the vm (maybe) (different
story, different problem).
As far as my goals are concerned, this try and and error of something as
simple as a stupid ping is slowing me down in developing guix services
for my roadmap items.

> I might be able to dig up notes on topology if you are interested. In 
> it, hypervisors form a VPN and integrate guests in the VPN using taps 
> and bridges. It's not a guix recipe unfortunately, just a Gnome Dia file.

I'm very much interested, throw anything at me which helps me to solve
this somehow.

> Best regards
>
>

[0] However, the lack of calling outside world is not gnunet exclusive.
-- 
              ng0