Direct Host Address

[Dan Kenigsberg]

On Thu, Feb 14, 2013 at 03:27:57PM -0500, Alon Bar-Lev wrote:
> 
> 
> ----- Original Message -----
> > From: "Muli Salem" <msalem at redhat.com>
> > To: "Mike Kolesnik" <mkolesni at redhat.com>
> > Cc: arch at ovirt.org
> > Sent: Sunday, February 10, 2013 6:09:30 PM
> > Subject: Re: Direct Host Address
> > > 
> > > "Current behaviour assumes the network interface with the specified
> > > address is configured properly in the engine although this may not
> > > be the case initially"
> > > 
> > > I don't understand what does this mean, which interface are you
> > > referring to and what does it have to do with being configured in
> > > the engine?
> > > The next line is also unclear to me:
> > > "The direct address allows the engine to connect to the host,
> > > without
> > > knowing the exact configuration of the network interface that has
> > > the address. "
> > > 
> > 
> > Regarding the last two sentences you quoted:
> > 
> > I am referring to the interface that has the IP that the user gives
> > us (with regards to current behavior).
> > At the moment, we assume that the given IP is for an interface that
> > can communicate with the engine (when in practice, this may not be
> > the case).
> > So separating the two addresses, allows us to ask the admin for an
> > alternate IP address that will allow communication without needing
> > to know the specific configuration (for example, whether this is a
> > VLAN network or not).
> > 
> > Perhaps the wording should be changed a bit to clarify.
> 
> I still don't get it... can you please provide real world use case?
> 
> When can we access the alternate address and not the management address?

We have customers who want to install vdsm via native connection, but
manage it over a VLAN. If you want to add a fresh host, you cannot use
its management address (that sits inside the vlan).