** No longer affects: nova/kilo -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to OpenStack Compute (nova). https://bugs.launchpad.net/bugs/1533876
Title: plug_vhostuser may fail due to device not found error when setting mtu Status in OpenStack Compute (nova): Fix Released Status in OpenStack Compute (nova) liberty series: In Progress Status in OpenStack Compute (nova) mitaka series: In Progress Bug description: Setting the mtu of a vhost-user port with the ip command will cause vms to fail to boot with a device not found error as vhost-user prots are not represented as kernel netdevs. this bug is present in stable/kilo, stable/liberty and master and i would like to ask that it be back ported if accepted and fixed in master. when using vhost-user with ovs-dpdk the vhost-user port is plugged into ovs by nova using a non atomic call to linux_net.create_ovs_vif_port to add an ovs port followed by a second call to linux_net.ovs_set_vhostuser_port_type to update the port type. https://github.com/openstack/nova/blob/1bf6a8760f0ef226dba927b62d4354e248b984de/nova/virt/libvirt/vif.py#L652-L655 the reuse of the create_ovs_vif_port has an untended concequece of introducing an error where the ip tool is invoked to try and set the mtu on the userspace vhost-user interface which dose not exist as a kernel netdev. https://github.com/openstack/nova/blob/1bf6a8760f0ef226dba927b62d4354e248b984de/nova/network/linux_net.py#L1379 this results in the in the call to set_device_mtu throwing an exception as the ip comand exits with code 1 https://github.com/openstack/nova/blob/1bf6a8760f0ef226dba927b62d4354e248b984de/nova/network/linux_net.py#L1340-L1342 as a result the second function call to ovs_set_vhostuser_port_type is never maid and the vm fails to boot. to resolve this issue i would like to introduce a new function to inux_net.py create_ovs_vhostuser_port which will create the vhostuser port as an atomic action and will not set the mtu similar to the impentation in the os-vif vhost-user driver https://github.com/jaypipes/vif_plug_vhostuser/blob/8ac30ce32b3e0bae5d2d8f1edc9d64ac2871608e/vif_plug_vhostuser/linux_net.py#L34-L46 an alternitive solution would be to add "1" to the retrun code check here https://github.com/openstack/nova/blob/master/nova/network/linux_net.py#L1339 or catch the exception here https://github.com/openstack/nova/blob/1bf6a8760f0ef226dba927b62d4354e248b984de/nova/virt/libvirt/vif.py#L652 however neither solve the underlying cause. this was observed with kilo openstack on ubuntu 14.04 with ovs-dpdk deployed with puppet/fule. To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1533876/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : [email protected] Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp
