Current Series Release Notes

New Features

  • Added support for ports with minimum guaranteed packet rate QoS policy rules. Support is provided for all server operations including cold migration, resize, interface attach/detach, etc. This feature required adding support for the port-resource-request-groups neutron API extension, as ports with such a QoS policy will have multiple rules, each requesting resources. For more details see the admin guide.

  • The nova-manage placement heal_allocations CLI now allows regenerating the placement allocation of servers with ports using minimum guaranteed packet rate QoS policy rules.

  • From this release, Nova instances will get virtio as the default display device (instead of cirrus, which has many limitations). If your guest has a native kernel (called “virtio-gpu” in Linux; available since Linux 4.4 and above) driver, then it’ll be used; otherwise, the ‘virtio’ model will gracefully fallback to VGA compatibiliy mode, which is still better than cirrus.

Known Issues

  • The libvirt virt driver in Nova implements power on and hard reboot by destroying the domain first and unpluging the vifs then recreating the domain and replugging the vifs. However nova does not wait for the network-vif-plugged event before unpause the domain. This can cause the domain to start running and requesting IP via DHCP before the networking backend has finished plugging the vifs. The config option [workarounds]wait_for_vif_plugged_event_during_hard_reboot has been added, defaulting to an empty list, that can be used to ensure that the libvirt driver waits for the network-vif-plugged event for vifs with specific vnic_type before it unpauses the domain during hard reboot. This should only be used if the deployment uses a networking backend that sends such event for the given vif_type at vif plug time. The ml2/ovs and the networking-odl Neutron backend is known to send plug time events for ports with normal vnic_type. For more information see

Upgrade Notes

  • The bandwidth field has been removed from the instance.exists and instance.update versioned notifications and the version for both notifications has been bumped to 2.0. The bandwidth field was only relevant when the XenAPI virt driver was in use, but this driver was removed in the Victoria (22.0.0) release and the field has been a no-op since.

Bug Fixes

  • Bug #1829479: Now deleting a nova-compute service removes allocations of successfully evacuated instances. This allows the associated resource provider to be deleted automatically even if the nova-compute service cannot recover after all instances on the node have been successfully evacuated.

  • Amended the guest resume operation to support mediated devices, as libvirt’s minimum required version (v6.0.0) supports the hot-plug/unplug of mediated devices, which was addressed in v4.3.0.

  • Bug 1950657, fixing behavior when nova-compute wouldn’t retry image download when gets “Corrupt image download” error from glanceclient and has num_retries config option set.

  • Fixes slow compute restart when using the nova.virt.ironic compute driver where the driver was previously attempting to attach VIFS on start-up via the plug_vifs driver method. This method has grown otherwise unused since the introduction of the attach_interface method of attaching VIFs. As Ironic manages the attachment of VIFs to baremetal nodes in order to align with the security requirements of a physical baremetal node’s lifecycle. The ironic driver now ignores calls to the plug_vifs method.