.. important::

   In deployments older than Train, or in mixed Stein/Train deployments with a
   rolling upgrade in progress, unless :oslo.config:option:`specifically
   enabled <workarounds.enable_numa_live_migration>`, live migration is not
   possible for instances with a NUMA topology when using the libvirt
   driver. A NUMA topology may be specified explicitly or can be added
   implicitly due to the use of CPU pinning or huge pages. Refer to `bug
   #1289064`__ for more information. As of Train, live migration of instances
   with a NUMA topology when using the libvirt driver is fully supported.

   __ https://bugs.launchpad.net/nova/+bug/1289064