[Engine-devel] bridgeless networks - update

[Itamar Heim]

On 02/16/2012 11:35 AM, Oved Ourfalli wrote:
...

>>> why does this matter if cluster is mixed?
>> to inform a potential migration problem
>>> i.e., wouldn't this be interesting per host, that a network which
>>> could
>>> be bridgeless http://www.ovirt.org/Features/Design/Network/SetupNetworks/is bridged to warn about?
>> I agree that an admin might like a notice that he can improve the
>> host's performance.
>> but currently how can we say a network can be bridgeless given that
>> we don't have the nic type yet?
>> detect if no vmInterfaces are connected to it maybe?
>>
> Itamar - It was decided to remove the "allow to run VMs" attribute on the logical network level (to simplify things, not sure it is the right way, though). AFAIU the main reason for that is that we might want to use a network for VMs in one cluster, and for other uses on another cluster. Not sure how important this use-case is, but in AFAIU that was the main reason to leave this attribute aside for now, and add it only later on.

I thought it was supposed to be per cluster (in the grand scheme of 
things, as part of also defining what would be the live migration 
networks, and things like that - all cluster level definitions).

btw, I may have missed the email on this change, but the wiki doesn't 
reflect it at all.

>
> If we indeed don't add this attribute then we can't really tell the admin "this network can be bridgeless" as we don't know that. Maybe the user wants to run VMs on it. So, we can just warn him in several scenarios that what he is doing is probably wrong, or we can monitor that and issue a warning event.
>
> If we do add this attribute then we can decide on a different logic: allowing only bridge for VM networks, allowing both but warn the user, monitoring for "mixed" configurations, and etc., according to what we think is a reasonable use-case.