Subject: Re: [vserver] Linux-VServer and net namespaces
From: Herbert Poetzl <herbert@13thfloor.at>
Date: Thu, 26 Nov 2009 00:00:48 +0100

On Wed, Nov 25, 2009 at 10:01:47PM +0100, Grzegorz Nosek wrote:
> Hi,

> Linux-VServers' networking isolation support doesn't really fit my
> use case too well (I'd like to have traffic *routed* from the outside
> world via the host to guests) so I tried to use network namespaces
> with VServer tools.

good!

> I see the recent util-vserver snapshots provide a tool called vspace
> and some options in /etc/vservers, although they don't configure the
> network in any meaningful way (e.g. by creating a macvlan device or a
> pair of veths or something).

patches are welcome I guess ....

> However, a bigger problem is related to putting network devices inside
> network namespaces -- the Linux-VServer kernel (2.6.31.6-vs2.3.0.36.24)
> oopses immediately, leaving the network stack unstable.

> I haven't saved the stack trace but the fix is attached -- looks like
> the cause was a simple mismerge so the fix is trivial too.

thanks, this is actually a leftover when mainline
network namespaces didn't work without this 'fix'
but obviously it wasn't remove when mainline fixed
the issue ...

> Please consider for the next release.

yep, will include that .. thanks again!

> On a related note, is anybody trying to make Linux-VServer coexist
> nicely with network namespaces? I'd rather not reinvent the wheel.

not much work has been done on that part, so feel
free to test and report any issues as well as submit
patches for inclusion and of course, write a wiki
page how to use them properly ...

> On a less related note, is there an easy way to determine guest init's
> pid (from the host's perspective)? 

/proc/virtual/<xid>/info contains the initpid as
seen from the host (for init virtualization)

> It's required for setting up (net) namespaces.

interesting ... how so?

TIA,
Herbert

> Best regards,
>  Grzegorz Nosek