Comment 3 for bug 1974352

by hiding the vm uuid and not providing the traceback its not really simple to triage this without prepping though all the logs.

i awas about to find what i belive is the error

2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi nova.exception_Remote.MigrationError_Remote: Migration error: 'e76b10a7-657d-4f33-9397-7014c24ad5cc'
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi Traceback (most recent call last):
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/conductor/manager.py", line 491, in _live_migrate
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi task.execute()
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/conductor/tasks/base.py", line 26, in wrap
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi self.rollback(ex)
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/oslo_utils/excutils.py", line 227, in __exit__
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi self.force_reraise()
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/oslo_utils/excutils.py", line 200, in force_reraise
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi raise self.value
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/conductor/tasks/base.py", line 23, in wrap
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi return original(self)
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/conductor/tasks/base.py", line 40, in execute
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi return self._execute()
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/powervc_nova/conductor/manager.py", line 661, in _execute
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi consumer_generation=None)
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi File "/usr/lib/python3.6/site-packages/nova/scheduler/utils.py", line 912, in claim_resources_on_destination
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi source_allocations[source_node.uuid]['resources']}
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi
2022-05-20 11:16:37.869 799631 ERROR nova.api.openstack.wsgi KeyError: 'e76b10a7-657d-4f33-9397-7014c24ad5cc'

that seam to indicate that there are not placement allocation for the instance on the source node.

so likely you need to run the heal allocation command before migrating the instance to repair the placement state.

https://docs.openstack.org/nova/latest/cli/nova-manage.html#placement-heal-allocations

can you confirm if that resolves the issue.