nova/doc/api_samples/os-volumes/snapshot-create-resp.json

{
    "snapshot": {
        "createdAt": "2013-02-25T16:27:54.680544",
        "displayDescription": "Daily backup",
        "displayName": "snap-001",
        "id": 100,
        "size": 100,
        "status": "available",
        "volumeId": "521752a6-acf6-4b2d-bc7a-119f9148cd8c"
    }
}