My VM can not be resize, but the flavor is subsistent exist

Question

I can not resize the VM, and get the bellow error:

In the /var/log/nova-api.log :

2017-10-11 16:53:07.796 24060 INFO nova.osapi_compute.wsgi.server [-] 118.113.57.187 "GET / HTTP/1.1" status: 200 len: 502 time: 0.0013940
2017-10-11 16:53:08.129 24060 INFO nova.api.openstack.wsgi [req-24f954ef-4e99-41d4-9700-26fa7204c863 - - - - -] HTTP Exception Thrown ：***Cloud hosting type flavor: 2Core1GB40GB1M did not found*** 。
2017-10-11 16:53:08.131 24060 INFO nova.osapi_compute.wsgi.server [req-24f954ef-4e99-41d4-9700-26fa7204c863 - - - - -] 118.113.57.187 "GET /v2.1/99a50773b170406b8902227118bb72bf/flavors/flavor:%202Core1GB40GB1M HTTP/1.1" status: 404 len: 485 time: 0.2736869
2017-10-11 16:53:08.248 24060 INFO nova.osapi_compute.wsgi.server [req-b7d1d426-b110-4931-90aa-f9cceeddb187 - - - - -] 118.113.57.187 "GET /v2.1/99a50773b170406b8902227118bb72bf/flavors HTTP/1.1" status: 200 len: 1913 time: 0.0570610
2017-10-11 16:53:08.565 24060 INFO nova.osapi_compute.wsgi.server [req-8cbc33a5-1a78-4ba7-8869-cf01536f784b - - - - -] 118.113.57.187 "POST /v2.1/99a50773b170406b8902227118bb72bf/flavors HTTP/1.1" status: 200 len: 875 time: 0.2515521
2017-10-11 16:53:10.433 24059 INFO nova.api.openstack.wsgi [req-42faeebb-d3ad-4e09-90e8-8da64f688fb9 - - - - -] HTTP Exception Thrown：***Can not find valid host，....***。
2017-10-11 16:53:10.435 24059 INFO nova.osapi_compute.wsgi.server [req-42faeebb-d3ad-4e09-90e8-8da64f688fb9 - - - - -] 118.113.57.187 "POST /v2.1/99a50773b170406b8902227118bb72bf/servers/f9bef431-0635-4c74-9af5-cf61ed4d3ae4/action HTTP/1.1" status: 400 len: 564 time: 1.6831121

No mater whatever flavor, the VM can not resize, but the flavor is subsistent.

Answer 1

Because my openstack is all in one server, so I can not migrate the VM( the resize essence is migrate), so I add this line in my nova.conf 's [DEFAULT]:

allow_resize_to_same_host=True

And restart the nova related service, I success:

# systemctl restart openstack-nova-api.service openstack-nova-cert.service openstack-nova-consoleauth.service openstack-nova-scheduler.service openstack-nova-conductor.service openstack-nova-novncproxy.service
# systemctl restart openstack-nova-compute.service 

Answer 2

For the two nodes configuration (controller and compute), I needed to include a couple of parameters more as it is explained here :

Update the “nova.conf” file in both controller and compute with the following lines

   allow_migrate_to_same_host = True
   scheduler_default_filters = AllHostsFilter
   allow_resize_to_same_host = True

Restart the following services of the "controller" node

• nova-api
• nova-cert
• nova-consoleauth
• nova-scheduler 
• nova-conductor
• nova-novncproxy

Restart the following service of the compute node:

• nova-compute