Add the Nova CpuFlagsFilter custom filter¶

CpuFlagsFilter is a custom Nova scheduler filter for live migrations. The filter ensures that the CPU features of a live migration source host match the target host. Use the CpuFlagsFilter filter only if your deployment meets the following criteria:

• The CPU mode is set to host-passthrough or host-model. For details, see MCP Deployment Guide: Configure a CPU model.
• The OpenStack compute nodes have heterogeneous CPUs.
• The OpenStack compute nodes are not organized in aggregates with the same CPU in each aggregate.

To add the Nova CpuFlagsFilter custom filter:

1. Open your project Git repository with the Reclass model on the cluster level.

2. Open the classes/cluster/<cluster_name>/openstack/control.yml file for editing.

3. Verify that the cpu_mode parameter is set to host-passthrough or host-model.

4. Add CpuFlagsFilter to the scheduler_default_filters parameter for nova:contoroller:

   nova:
     controller:
       scheduler_default_filters: “DifferentHostFilter,SameHostFilter,RetryFilter,AvailabilityZoneFilter,RamFilter,CoreFilter,DiskFilter,ComputeFilter,ComputeCapabilitiesFilter,ImagePropertiesFilter,ServerGroupAntiAffinityFilter,ServerGroupAffinityFilter,PciPassthroughFilter,NUMATopologyFilter,AggregateInstanceExtraSpecsFilter,CpuFlagsFilter”
   

5. Log in to the Salt Master node.

6. Apply the changes:

   salt -C 'I@nova:controller' state.sls nova.controller