[ovirt-users] Problemas with ovirtmgmt network used to connect VMs

[Edward Haas]

Hello Fernando,

Have you taken the tcpdump in the VM to see what traffic is sent out?
Your host is a Centos 7.3? If so how come it has such a kernel version?

Have you see anything in /var/log/messages when it gets disconnected?

Thanks,
Edy.


On Fri, Jul 28, 2017 at 9:01 PM, FERNANDO FREDIANI <
fernando.frediani at upx.com> wrote:

> Hello Edwardh and all.
>
> I keep getting these disconnects, were you able to find anything about to
> suggest changing ?
>
> As I mentioned this machine different from the others where it never
> happened uses the ovirtmgmt network as VM network and has kernel 4.12
> instead of the default 3.10 from CentOS 7.3. It seems a particular
> situation that is triggering this behavior but could not gather any hint
> yet.
>
> I have tried to run a regular arping to force the bridge always learn the
> VMs MAC address but it doesn't seem to work and every in a while the bridge
> 'forgets' that particular VM mac address.
> I have also even rebuilt the VM completely changing its operating system
> from Ubuntu 16.04 to CentOS 7.3 and the same problem happened.
>
> Fernando
>
> On 24/07/2017 18:20, FERNANDO FREDIANI wrote:
>
> Hello Edward, this happened again today and I was able to check more
> details.
>
> So:
>
> - The VM stopped passing any network traffic.
> - Checking 'brctl showmacs ovirtmgmt' it showed the VM's mac address
> missing.
> - I then went to oVirt Engine, under VM's 'Network Interfaces' tab,
> clicked Edit and changed the Link State to Down then to Up and it recovered
> its connectivity.
> - Another 'brctl showmacs ovirtmgmt' showed the VM's mac address learned
> again by the bridge.
>
> This Node server has the particularity of sharing the ovirtmgmt with VMs.
> Could it possibly be the cause of the issue in any way ?
>
> Thanks
> Fernando
>
> On 24/07/2017 09:47, FERNANDO FREDIANI wrote:
>
> Not tried this yet Edwardh, but will do at next time it happens. THe
> source mac address should be the mac as the VM. I don't see any reason for
> it to change from within the VM ou outside.
>
> What type of things would make the bridge stop learning a given VM mac
> address ?
>
> Fernando
>
> On 23/07/2017 07:51, Edward Haas wrote:
>
> Have you tried to use tcpdump at the VM vNIC to examine if there is
> traffic trying to get out from there? And with what source mac address?
>
> Thanks,
> Edy,
>
> On Fri, Jul 21, 2017 at 5:36 PM, FERNANDO FREDIANI <
> fernando.frediani at upx.com> wrote:
>
>> Has anyone had problem when using the ovirtmgmt bridge to connect VMs ?
>>
>> I am still facing a bizarre problem where some VMs connected to this
>> bridge stop passing traffic. Checking the problem further I see its mac
>> address stops being learned by the bridge and the problem is resolved only
>> with a VM reboot.
>>
>> When I last saw the problem I run brctl showmacs ovirtmgmt and it shows
>> me the VM's mac adress with agening timer 200.19. After the VM reboot I see
>> the same mac with agening timer 0.00.
>> I don't see it in another environment where the ovirtmgmt is not used for
>> VMs.
>>
>> Does anyone have any clue about this type of behavior ?
>>
>> Fernando
>> _______________________________________________
>> Users mailing list
>> Users at ovirt.org
>> http://lists.ovirt.org/mailman/listinfo/users
>>
>
>
>
>
>
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