It seems that multinic migration db is not done for unmanaged hosts.
We have errors during chef facts import like :

RuntimeError: Host::Base#domain= delegated to primary_interface.domain=, but primary_interface is nil: #<Host::Managed id: 110, name: "xxx", last_compile: "2015-02-01 20:02:26", last_freshcheck: nil, last_report: "2015-02-01 19:53:35", updated_at: "2015-02-01 20:02:32", source_file_id: nil, created_at: "2014-11-26 00:24:43", root_pass: "$6$xxx", serial: nil, puppet_status: 0, architecture_id: nil, operatingsystem_id: 1, environment_id: 6, ptable_id: nil, medium_id: nil, build: false, comment: nil, disk: nil, installed_at: nil, model_id: nil, hostgroup_id: nil, owner_id: nil, owner_type: nil, enabled: true, puppet_ca_proxy_id: nil, managed: false, use_image: nil, image_file: nil, uuid: nil, compute_resource_id: nil, puppet_proxy_id: nil, certname: nil, image_id: nil, organization_id: nil, location_id: nil, type: "Host::Managed", otp: nil, realm_id: nil, compute_profile_id: nil, provision_method: nil, grub_pass: "$6$xxx", chef_proxy_id: nil>