Forgive my short reply but do you have a lot of VMs on these machines by any 
chance?  We've seen issues with libvirt taking a long time with a large number 
of VMs as it sets up all the network filters. 

Sent from my iPhone

> On Feb 22, 2017, at 10:33 AM, Edmund Rhudy (BLOOMBERG/ 120 PARK) 
> <[email protected]> wrote:
> 
> I recently witnessed a strange issue with libvirt when upgrading one of our 
> clusters from Kilo to Liberty. I'm not really looking for a specific 
> diagnosis here because of the large number of confounding factors and the 
> relative ease of remediating it, but I'm interested to hear if anyone else 
> has witnessed this particular problem.
> 
> Background is we had a number of Kilo-based clusters, all running Ubuntu 
> 14.04.4 with OpenStack installed from the Ubuntu cloud archive. The upgrade 
> process to Liberty involved upgrading the OpenStack components and their 
> dependencies (including libvirt), then afterward upgrading all remaining 
> packages via dist-upgrade (and staging a kernel upgrade from 3.13 to 4.4, to 
> take effect on the next reboot). 7 clusters had all been upgraded 
> successfully using this strategy.
> 
> One cluster, however, decided to get a bit weird. After the upgrade, 4 
> hypervisors showed that nova-compute was refusing to come up properly and was 
> showing as enabled/down in nova service-list. Upon further investigation, 
> nova-compute was starting up but was getting jammed on loading nwfilters. 
> When I ran "virsh nwfilter-list", the command stalled indefinitely. Killing 
> nova-compute and restarting libvirt-bin service allowed the command to work 
> again, but it did not list any of the nova-instance-instance-* nwfilters. 
> Once nova-compute was started, it tried to start loading the 
> instance-specific filters and libvirt would wedge. I spent a while tinkering 
> with the affected systems but could not find any way of correcting the issue 
> other than rebooting the hypervisor, after which everything was fine.
> 
> Has anyone ever seen anything like this? libvirt was upgraded from 1.2.12 to 
> 1.2.16. Hundreds of hypervisors had already received this exact same upgrade 
> without showing this problem, and I have no idea how I could reproduce it. 
> I'm interested to hear if anyone else has ever run into this and if they 
> figured out what the root cause was, though I've already braced myself for 
> tumbleweeds.
> _______________________________________________
> OpenStack-operators mailing list
> [email protected]
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
_______________________________________________
OpenStack-operators mailing list
[email protected]
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators

Reply via email to