On a related note, I just did a resize of an instance from a flavor with dedicated CPUs, 2 cpus and no specified numa information to a flavor with dedicated CPUs, 2 cpus and two NUMA nodes.
As part of the resize this ended up triggering a switch to another compute node. Also, the XML file for the instance being started up did not reflect the NUMA settings for the new flavor.
Lastly, as per above the host cpus were not re-evaluated on the new compute node and so ended up using host cpus that were already in use by another instance with dedicated CPUs.
On a related note, I just did a resize of an instance from a flavor with dedicated CPUs, 2 cpus and no specified numa information to a flavor with dedicated CPUs, 2 cpus and two NUMA nodes.
As part of the resize this ended up triggering a switch to another compute node. Also, the XML file for the instance being started up did not reflect the NUMA settings for the new flavor.
Lastly, as per above the host cpus were not re-evaluated on the new compute node and so ended up using host cpus that were already in use by another instance with dedicated CPUs.