Affinity groups

--config '{additionalParamsForVnf: [{member-vnf-index: "1", additionalParams: {touch_filename: your-value,  touch_filename2: your-value2}}]}'

```

### Specifying an affinity-or-anti affinity group

Affinity-or-anti-affinity groups may be defined in the VNF descriptor, in the `df` section, under `affinity-or-anti-affinity-group`.

The type may be `affinity` or `anti-affinity`, and the scope must be `nfvi-node`. VDU profiles may reference one of the defined affinity-or-anti-affinity-group. Notice that, in Openstack, only one group is allowed. The following example shows a VNF with two VDU, both assigned to the same affinity-group `affinity-group-1`. Both virtual machines will be then instantiated in the same host.

```yaml

vnfd:

  description: A basic VNF descriptor w/ two VDUs and an affinity group

  df:

  - id: default-df

    instantiation-level:

    - id: default-instantiation-level

      vdu-level:

      - number-of-instances: 1

        vdu-id: affinity_basic-VM-1

      - number-of-instances: 1

        vdu-id: affinity_basic-VM-2

    vdu-profile:

    - id: affinity_basic-VM-1

      min-number-of-instances: 1

      affinity-or-anti-affinity-group:

      - id: affinity-group-1

    - id: affinity_basic-VM-2

      min-number-of-instances: 1

      affinity-or-anti-affinity-group:

      - id: affinity-group-1

    affinity-or-anti-affinity-group:

    - id: affinity-group-1

      type: affinity

      scope: nfvi-node

```

An existing server-group may be passed as an instantiation parameter to be used as affinity-or-anti-affinity-group. In this case, the server-group will not be created, but reused, and will not be deleted when the Network Service instance is deleted. The following example shows the syntax

```yaml

 --config '{additionalParamsForVnf: [{member-vnf-index: affinity-basic-1, affinity-or-anti-affinity-group: [{ id: affinity-group-1, "vim-affinity-group-id": "81b82372-bbd4-48d6-b368-4d0b9d04d592"}]}]}'

```

Where the `id` of the `affinity-or-anti-affinity-group` is the one in the descriptor, and the `vim-affinity-group-id` is the guid of the existing server-group in Openstack to be used (instead of being created).

## Understanding Day-1 and Day-2 Operations

VNF configuration is done in three "days":