[ovirt-users] 答复: bonding 802.3ad mode

[Nathanaël Blanchet]

Hello Dan,

Initially, I wanted to reduce the time of import process from the export 
domain to my FC storage domain. In this context, I'm not limited by the 
SAN (8Gbits) or the disk I/O (raid 5), but by the gigabit NIC.
My initial network configuration was to aggregate 2 nic (1 and 3) to a 
mode 4 bond0 and making vlan over it. So mode 4 is the best mode for 
this because each vms ha its own MAC adress, so the 2gigabits BW are 
used as expected.
But the problematic of importing vms (the same as migrating them) is not 
the same, because the flow is unique, so the bandwith is never useful.
What I decided to do, is to create a second non-LACP bridge bond1 
aggragating nic2 and nic4 which is dedicated to the ovirtmgmt bridgeless 
network.
Because this one is bridgeless, I add in the custom field the "mode=4 
miion=100) options to have the round robin mode.
It seems to be ok after testing... please, tell me if I do something wrong.

Le 23/03/2015 10:32, Dan Kenigsberg a écrit :
> On Fri, Mar 20, 2015 at 04:48:29PM +0100, Nathanaël Blanchet wrote:
>> Hello, thanks for the explanation, but I did'nt find any reason about
>> incompatibility between mode 0 and bridge... Can you give me some sources
>> about this? Ovirt doesn't actually allow it, so it must exist a good reason
>> for that.
> I can quote Jiri Pirko
> https://bugzilla.redhat.com/show_bug.cgi?id=1094842#c0
> """
> Do not use tlb or alb in bridge, never! It does not work, that's it. The
> reason is it mangles source macs in xmit frames and arps. When it is
> possible, just use mode 4 (lacp). That should be always possible because
> all enterprise switches support that. Generally, for 99% of use cases,
> you *should* use mode 4. There is no reason to use other modes.
> """
>
>> But for my own, I have several single kvm hosts that support bridge over
>> bonding in mode 0 and vms run fine on it...
>> So, someone can share his experience about this kind of detail?
>>
>> ps: ovirt has a field for configuring custom mode whereas mode 0 is not
>> listed in the predifined list, I didn't make any test, but it seem to be at
>> least possible.
> The bug referred above intends to make it a bit harder to make this
> mistake. But in the good-old Un*x way, oVirt allows you to tweak things
> that you actually should not, for fun or research.