Description of problem:
Adding new network with vlan tag, ovirt doesn't allow duplicate VLAN IDs.
But it should be allowed, because if you are using multiple interfaces you can have the same vlan ID as long as they aren't assigned to the same interface on the hardware node.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Just add network with same vlan id as an already added interface.
See email thread labeled "Re: [ovirt-users] multiple NICs VLAN ID conflict".
GUI says vlan already used.
Duplicate VLAN ID should be checked when you are assign network to the hardware node, not when creating the interface.
Trying to work around this with vdsm hooks in before_network_setup, after_get_caps and after_get_stats is very difficult to get it to work right. (see email thread)
Perhaps only WARN.
(In reply to Yaniv Kaul from comment #1)
> Perhaps only WARN.
Just warning at network creation time would be fine too.
Any chance I could get a "patch" or "hack" that could change the rejection to a warning?
Unfortunately this is holding up me being able to deploy oVirt.
I'm afraid that we should fix Engine to accept this. Yevgeni, how hard is the fix?
Bill, can you add a reference to the email thread? I'd like to understand which problem you have seen with implementing this with a vdsm hook.
The change on the engine side for the "add network" flow seems quite easy to me.
However it might break some decisions that were made based on the assumption that VLAN_ID is unique across a DC networks.
Bill, could you please explain the use-case where multiple networks could bear the same VLAN_ID in a single data-center?
We have 4 different switches in our prod datacenter that cover different products and usage requirements. We want to keep some products separate from others which is why they have their own switch and set of subnets.
Since they are separate switches there was no need to be concerned about keeping VLAN IDs unique across switches.
With virtualization we don't mind mixing products on same hardware, but want to keep network traffic separated. So our hardware nodes have 8 NICs to handle all the different network switches. Our previous virtualization platform didn't have any problem with duplicate VLAN IDs so this wasn't an issue. Until we tried to move to oVirt.
I've created the Gerrit patch  that removes the validation.
Please let us know if you're able to consume the patch (build oVirt from its sources) and if the patch does what you ask for.
The request was discussed on http://lists.ovirt.org/pipermail/users/2016-March/038463.html
sorry, I haven't had a chance to setup a build host for ovirt yet so haven't tested the patch.
As I can see, the gerrit case is abandoned, what's the real status of this request? What is needed, to get this accepted and included in ovirt?
(In reply to Steffen Froemer from comment #10)
> As I can see, the gerrit case is abandoned, what's the real status of this
> request? What is needed, to get this accepted and included in ovirt?
It is not POST, there are no plans currently to enable this for 4.1. The only option is to consider it for 4.2.
This request has been proposed for two releases. This is invalid flag usage. The ovirt-future release flag has been cleared. If you wish to change the release flag, you must clear one release flag and then set the other release flag to ?.
Verified on - 4.2.0-0.0.master.20170707124946.gitf15a6d9.el7.centos
1) Create networks with same vlan IDs in the DC
2) Attach networks with same vlan IDs to the same host(not one interface)
3) Validate when trying to attach networks with same vlan IDs to one interface on the host
Verified on - 4.1.4-0.2.el7