More than 1219 VMs on a single compute node causes issues with external network and VNC connections

Solution In Progress - Updated -

Issue

  • When we get around 1220 VMs on a compute node, the external network stops working (can't ping out) and the VNC connections no longer connect. As soon as there are fewer than 1220 VMs, connection to the external network starts working and VNC connection start working.

  • We see the following messages in /var/log/messages:

Jun 29 17:20:57 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:20:57 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:20:59 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:20:59 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:21:00 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:21:07 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:21:07 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:21:07 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:21:07 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:21:08 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:21:08 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:21:08 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:21:13 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:21:13 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:21:14 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:21:14 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:21:15 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768
Jun 29 17:21:15 compute00 kernel: openvswitch: netlink: Flow action size exceeds max 32768

Environment

  • Red Hat OpenStack Platform 16.2 (RHOSP)

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