protocol:
{
  "driver": "gluster",
  "location": {
    "volume": "asdf",
    "path": "i.qcow2",
    "server": [
      {
        "type": "inet",
        "host": "example.com",
        "port": "1234"
      },
      {
        "type": "inet",
        "host": "alternate.example.com",
        "port": "3214"
      }
    ]
  },
  "size": 42
}

format:
{
  "driver": "qcow2",
  "file": "0123456789ABCDEF0123456789ABCDE",
  "size": 1337
}