cinder/api-ref/source/v3/samples/volume-force-detach-request.json

{
    "os-force_detach": {
        "attachment_id": "d8777f54-84cf-4809-a679-468ffed56cf1",
        "connector": {
            "initiator": "iqn.2012-07.org.fake:01"
        }
    }
}