[Devel] Re: [patch 2/6] [Network namespace] Network device sharing by view

[jamal]

Andrey,

On Wed, 2006-28-06 at 18:19 +0400, Andrey Savochkin wrote:
> Hi Jamal,
> 
> On Wed, Jun 28, 2006 at 09:53:23AM -0400, jamal wrote:
> > 

> 
> Seeing guestXX-eth0 interfaces by standard tools has certain attractive
> sides.  But it creates a lot of undesired side effects.
> 

I apologize because i butted into the discussion without perhaps reading
the full thread. 

> For example, ntpd queries all network devices by the same ioctls as ifconfig,
> and creates separate sockets bound to IP addresses of each device, which is
> certainly not desired with namespaces.
> 

Ok, so the problem is that ntp in this case runs on the host side as
opposed to the guest? This would explain why Eric is reacting vehemently
to the suggestion.

> Or more subtle question: do you want hotplug events to be generated when
> guest0-eth0 interface comes up in the root namespace, and standard scripts
> to try to set some IP address on this interface?..
> 

yes, thats what i was thinking. Even go further and actually create
guestxx-eth0 on the host (which results in creating eth0 on the guest)
and other things.

> In my opinion, the downside of this scheme overweights possible advantages,
> and I'm personally quite happy with running commands with switched namespace,
> like
> vzctl exec guest0 ip addr list
> vzctl exec guest0 ip link set eth0 up
> and so on.

Ok, above may be good enough and doesnt require any state it seems on
the host side. 
I got motivated when the word "migration" was mentioned. I understood it
to be meaning that a guest may become inoperative for some reason and
that its info will be transfered to another guest which may be local or
even remote. In such a case, clearly one would need a protocol and the
state of all guests sitting at the host. Maybe i am over-reaching. 

cheers,
jamal