How to resize Nova instance

Obtain the UUID of the desired flavor

openstack flavor list

Resize the server:

openstack server resize --flavor <flavor_UUID> <instance_name_or_UUID>

At this point, Nova will perform a graceful shutdown of the specified instance and allow 60 seconds for it to complete.

Check the status of the resize operation by running

openstack server show <UUID/name>

Confirm the resize

openstack server migration confirm <instance_name_or_UUID>

If there are any issues, the operation can be reverted by executing:

openstack server migration revert <instance_name_or_UUID>