---
fixes:
  - |
    An instance can be rebuilt in-place with the original image or a new
    image. Instance resource usage cannot be altered during a rebuild.
    Previously Nova would have ignored the NUMA topology of the new image
    continuing to use the NUMA topology of the existing instance until a move
    operation was performed. As Nova did not explicitly guard against
    inadvertent changes in resource request contained in a new image,
    it was possible to rebuild with an image that would violate this requirement
    `bug #1763766`_. This resulted in an inconsistent state as the instance that
    was running did not match the instance that was requested. Nova now explicitly
    checks if a rebuild would alter the requested NUMA topology of an instance
    and rejects the rebuild.

    ..  _`bug #1763766`: https://bugs.launchpad.net/nova/+bug/1763766