Queens Series Release Notes¶

17.0.4-22¶

This role now optionally enables your compute nodes’ KVM kernel module nested virtualization capabilities, by setting nova_nested_virt_enabled to true. Depending on your distribution and libvirt version, you might need to set additional variables to fully enabled nested virtualization. For details, please see https://docs.openstack.org/nova/latest/admin/configuration/hypervisor-kvm.html#nested-guest-support.

You can now set the Libvirt CPU model and feature flags from the appropriate entry under the nova_virt_types dictionary variable (normally kvm). nova_cpu_model is a string value that sets the CPU model; this value is ignored if you set any nova_cpu_mode other than custom. nova_cpu_model_extra_flags is a list that allows you to specify extra CPU feature flags not normally passed through with host-model, or the custom CPU model of your choice.

With the release of CentOS 7.5, all pike releases are broken due to a mismatch in version between the libvirt-python library specified by the OpenStack community, and the version provided in CentOS 7.5. As such OSA is unable build the appropriate python library for libvirt. The only recourse for this is to upgrade the environment to the latest queens release.

If your configuration previously set the libvirt/cpu_model and/or libvirt/cpu_model_extra_flags variables in a nova_nova_conf_overrides dictionary, you should consider moving those to nova_cpu_model and nova_cpu_model_extra_flags in the appropriate entry (normally kvm) in the nova_virt_types dictionary.

The variable nova_compute_pip_packages is no longer used and has been removed.

In order to prevent further issues with a libvirt and python-libvirt version mismatch, KVM-based compute nodes will now use the distribution package python library for libvirt. This should resolve the issue seen with pike builds on CentOS 7.5.

Added the ability to configure vendor data for Nova in order to be able to push things via the metadata service or config drive.

The default variable nova_default_schedule_zone was previously set by default to nova. This default has been removed to allow the default to be set by the nova code instead. Deployers wishing to maintain the default availability zone of nova must now set the variable as a user_variables.yml or group_vars override.

Enable Kernel Shared Memory support by setting nova_compute_ksm_enabled to True.

KSM configuration is changed to disabled by default on Ubuntu. If you overcommit the RAM on your hypervisor it’s a good idea to set nova_compute_ksm_enabled to True.

The variables nova_scheduler_use_baremetal_filters and nova_metadata_host have been removed, matching upstream nova changes. The nova_virt_types dict no longer needs the nova_scheduler_use_baremetal_filters and nova_firewall_driver keys as well.