--- upgrade: - | During the triage of https://bugs.launchpad.net/nova/+bug/1978372 we compared the performance of nova's numa allocations strategies as it applied to the large numbers of host and guest numa nodes. Prior to ``Xena`` nova only supported a linear packing strategy. In ``Xena`` ``[compute]/packing_host_numa_cells_allocation_strategy`` was introduced maintaining the previous packing behavior by default. The numa allocation strategy has now been defaulted to spread. The old behavior can be restored by defining: ``[compute]/packing_host_numa_cells_allocation_strategy=true``