[vdsm] [RFC] ipv6 support of vdsm

Daniel P. Berrange berrange at redhat.com
Thu Nov 8 21:35:23 UTC 2012


On Thu, Nov 08, 2012 at 11:25:19PM +0200, Dan Kenigsberg wrote:
> On Thu, Nov 08, 2012 at 06:58:09PM +0800, huntxu wrote:
> > Hi, folks.
> > 
> > Recently I am considering to implement ipv6 support for vdsm. First
> > of all I
> > would like to know whether there is already someone working on this
> > feature.
> 
> I am not aware of anyone working on ipv6 at the momemnt. You are more
> than welcome to lead the way!
> 
> > If so, I might do something to help, however, if not, I would try to
> > implement
> > it with suggestions from this discussion.
> > 
> > With ipv6 support vdsm is supposed to work properly in:
> >     * mixed environment, in which ipv4 and ipv6 addresses coexist
> >     * ipv6-pure environment
> > 
> > My idea is:
> > 
> > 1) Provide a mechanism to setup ipv6 address configuration of a host via
> > XMLRPC/RestAPI. This would be done in the current ConfigNetwork module by
> > modifying the network-scripts/ifcfg-* of the devices. Thus the host is
> > able to access ipv6 network (with correct configuration).
> 
> Host network configuration is an important part. We would have to report
> ipv6 addresses, too.
> 
> Please keep in mind, that we would like to move away from direct ifcfg
> mangaling since it's distribution-dependent, and not even the common
> practice in modern Fedoras. (sob)

I'd love to see VDSM start to make use of libvirt's network interface
APIs, since we added all that support for making transaction config
changes for the benefit of VDSM :-)  It of course supports IPv6
configuration already, and would get you portability to Debian, Suse
and soon BSD via NetCF.

> > 5) The management connection is supposed to be able to switch between ipv4
> > and ipv6 on the fly (when host is under maintenance and with proper network
> > configuration of the host). This requires another vdsm API.
> 
> This problem is already with us - if vdsm.conf is configured to listen
> on one address, and a setupNetwork call changes the management network
> address to something else, I'm pretty sure that we'd get disconnected.
> This bug is not widely noticed, since vdsm listens to all ip addresses
> by default.
> 
> 6) migration over ipv6,

If you pass libvirt a hostname for the migration target, libvirt
should will do correct DNS resolution to work with IPv6, and so
should QEMU.

If you pass libvirt a raw IPv4 address, then obviously you'll
need some work to switch to passing IPv6 addrs. The main thing
to be aware of is the need to use [] around the address if
including it in a URI 

Regards,
Daniel
-- 
|: http://berrange.com      -o-    http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org              -o-             http://virt-manager.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org       -o-       http://live.gnome.org/gtk-vnc :|


More information about the vdsm-devel mailing list