OVS agent updates the wrong port when using XenAPI + Neutron with HVM or PVHVM
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
OpenStack Compute (nova) |
Fix Released
|
Undecided
|
Unassigned |
Bug Description
Environment
==========
- Xen Server 6.2
- OpenStack Havana installed with Packstack
- Neutron OVS agent using VLAN
From time to time, when an instance is started, it fails to get network connectivity. As a result the instance cannot get its IP address from DHCP and it remains unreachable.
After further investigation, it appears that the OVS agent running on the compute node is updating the wrong OVS port because on startup, 2 ports exist for the same instance: vifX.0 and tapX.0. The agent updates whatever port is returned in first position (see logs below). Note that the tapX.0 port is only transient and disappears after a few seconds.
Workaround
==========
Manually update the OVS port on dom0:
$ ovs-vsctl set Port vif17.0 tag=1
OVS Agent logs
============
2014-01-14 14:15:11.382 18268 DEBUG neutron.
2014-01-14 14:15:11.403 18268 DEBUG qpid.messaging.
2014-01-14 14:15:11.649 18268 DEBUG neutron.
Command: ['/usr/
Exit code: 0
Stdout: 'external_ids : {attached-
Stderr: '' execute /usr/lib/
2014-01-14 14:15:11.650 18268 INFO neutron.
2014-01-14 14:15:11.650 18268 DEBUG neutron.
2014-01-14 14:15:11.913 18268 DEBUG neutron.
Command: ['/usr/
Exit code: 0
Stdout: '\n'
Stderr: '' execute /usr/lib/
tags: | added: xenserver |
summary: |
- OVS agent updates the wrong port when using Xen + Neutron + OVS agent updates the wrong port when using Xen + Neutron with HVM |
tags: | added: ovs |
Changed in neutron: | |
assignee: | nobody → Bob Ball (bob-ball) |
Changed in neutron: | |
status: | Opinion → Incomplete |
tags: | removed: havana-backport-potential |
Changed in neutron: | |
status: | In Progress → Incomplete |
assignee: | Jianghua Wang (wjh-fresh) → nobody |
Changed in neutron: | |
status: | Incomplete → Fix Committed |
affects: | neutron → nova |
summary: |
- OVS agent updates the wrong port when using Xen + Neutron with HVM or + OVS agent updates the wrong port when using XenAPI + Neutron with HVM or PVHVM |
Changed in nova: | |
status: | Fix Committed → Fix Released |
I just realized that this is because I'm using HVM instances. In that case, Xen Server creates 1 vif and 1 tap and it deletes the tap interface if the domU is able to load the virtualized Xen driver for the NIC. lists.xen. org/archives/ html/xen- devel/2011- 12/msg02085. html
See http://