snip
  "storage": {
    "filesystems": [
      {
        "mount": {
          "device": "/dev/sda1",
          "format": "xfs",
          "wipeFilesystem": false
        },
        "name": "persistent-volume"
      }
    ],
    "files": [
snip
  },
  "systemd": {
    "units": [
      {
        "contents": "[Unit]\nBefore=local-fs.target\n[Mount]\nWhat=/dev/sda1\nWhere=/mnt/persistent-volume/\nType=xfs\n[Install]\nWantedBy=local-fs.target",
        "enable": true,
        "name": "mnt-persistent\x2dvolume.mount"
      },
snip
    ]
  }
}