We discussed this in the nova meeting today [1] with a little spillover in the -nova channel afterward [2]. The consensus was: Don't muck with resource provider traits at all during aggregate operations. The operator must do that bit manually. As a stretch goal, we can write a simple utility to help with this. This was discussed as option (e) earlier in this thread. The spec needs to get updated accordingly. Thanks, efried [1] http://eavesdrop.openstack.org/meetings/nova/2019/nova.2019-06-13-14.00.log.html#l-267 [2] http://eavesdrop.openstack.org/irclogs/%23openstack-nova/%23openstack-nova.2019-06-13.log.html#t2019-06-13T15:02:06-2 (interleaved)