[ovirt-users] Guest PXE boot with 2 NICs : MAC order

[Nicolas Ecarnot]

Le 31/03/2015 13:57, Lior Vernia a écrit :
>
>
> On 31/03/15 14:21, Nicolas Ecarnot wrote:
>> Hi Lior,
>>
>> Le 31/03/2015 12:55, Lior Vernia a écrit :
>>> Indeed, if you're using oVirt 3.4 and up, and you supply all the NICs
>>> whenever you create the VM (not afterwards - as part of the new VM
>>> dialog), the NICs should receive MAC addresses according to their
>>> ordering by names, e.g. nic1 will always get a lower MAC address than
>>> nic2. For a newly-created VM this should guarantee that nic1 will indeed
>>> end up the first NIC inside the guest OS and be used by PXE.
>>
>> In the BZ I provided above, I explain that my tests are showing that
>> this is not true : the nics are not yet sorted according to their MAC
>> nor their names.
>>
>> I'm using 3.5.1
>>
>
> I see. It seems MAC addresses are allocated according to the NIC name
> order,

I'm not sure this is exact.
According to what I'm witnessing, MAC addresses are allocated in 
incremental order, from the first free MAC address in the MAC pool range.

> and that they are also named in the corresponding order within
> the guest OS.

Er.. what gives when I'm naming my interfaces ethX, and amongst that, 
oVirt comes trying to add some nicX???

> So the only problem here is how gPXE chooses a NIC to boot
> from... I'm not familiar with the behavior of gPXE, but oVirt seems to
> behave alright.

I mostly agree with that, in the sense that one has to dig in which way 
gPXE is sorting the NICs, ie mapping the MACs to its "net0", "net1", and 
so on.

And then, decide whether oVirt could have a control upon this sorting, 
and then issue a RFE to master it from the web GUI.

-- 
Nicolas ECARNOT

>
>>>
>>> If this is something you do a lot, then I'd suggest creating a new
>>> template as such and create VMs from that.
>>
>> I know that could be a way, but this is not our strategy, as we prefer
>> using kickstart and we have so many different setups that factorisation
>> is not possible.
>>
>>>
>>> On 31/03/15 11:23, Nicolas Ecarnot wrote:
>>>> Le 31/03/2015 09:21, Sven Kieske a écrit :
>>>>> You should file an RFE on bugzilla for this
>>>>> kind of stuff and maybe raise awareness during
>>>>> the weekly meeting on irc.
>>>>>
>>>>> this increases the chance of an implementation
>>>>> taking place dramatically ;)
>>>>>
>>>>> HTH
>>>>>
>>>>>
>>>>
>>>> Hi Sven,
>>>>
>>>> I found and append this :
>>>> https://bugzilla.redhat.com/show_bug.cgi?id=1045022
>>>>
>>
>>


-- 
Nicolas Ecarnot