On Mon, Dec 14, 2015 at 09:00:22PM +0800, Peter Xu wrote: > On Mon, Dec 14, 2015 at 08:09:37PM +0800, Yuanhan Liu wrote: > > It seems that we have exactly the same test environment set up: I have > > one server (where I normally do vhost test there) and one desktop (my > > dev box), > > > > On both hosts, there is an ovs bridge, with IP address 192.168.100.1 > > assigned manually. Later, I started a VM on the server, and manually > > assigned IP to 192.168.100.10. I then run "ping 192.168.100.1" for > > live migration testing. > > > > The migration to my desktop somehow works (even though there are some > > bugs in this patch set), however, I did see what Pavel saw: about 12 > > packets has been lost, which means about 12 seconds the network is not > > working well. > > Hi, Yuanhan, > > I _guess_ the problem for ping might be: guest ARP entry for > 192.168.100.1 is not updated. Or say, after guest migrated to host2 > from host1, guest is still trying to send packet to host1's NIC (no > one is telling it to update, right?), so no one is responding the > ping. When the entry is expired, guest will resend the ARP request, > and host2 will respond this time, with mac address on host2 provided > this time. After that, ping works again.
Peter, Thanks for your input, and that sounds reasonable. You just reminded me that the host1's NIC is indeed different with host2's NIC: the ovs bridge mac address is different. I then had a quick try, setting the two ovs bridge with same mac address, and it works like a charm: the gap is gone :) --yliu > > (not familiar with OVS too, so am just taking it as a "vritual" > switch) > > Thanks. > Peter