So for the past month we've been trying to troubleshoot a problem that has me completely stumped. The symptoms are as described here by someone else experiencing the same problem:
http://askubuntu.com/questions/456325/packet-loss-between-guests-under-kvm-qemu/510553#510553
I can tell you what it's not:-
- It's not KSM. KSM is disabled on the hosts.
- It's not NUMA. It's not a NUMA machine.
- It's not net.bridge.bridge-nf-call-iptables
- It's not udev. We've configured it to ignore libvirt qemu interfaces.
- It's not spanning tree. It's disabled everywhere.
The symptoms are that all guests on a host lose all network connectivity for 28 seconds at the same time.
Note this happens to our FreeBSD (pfSense) guests as well as our Ubuntu 14.0 hosts so I don't think it's anything the guests are doing.
I'd be super grateful if anyone has any ideas that might help us. This is a real show stopper for us, and we've used all the google-fu we can, and the only thing that we've found so far is the above things, and nothing helps. The post from April is tantalizingly similar, a relevant xkcd applies here.
Plz halp.
[link][10 comments]