Read Disk data

Example response

{
  "data": [
    {
      "device": "/dev/sda1",
      "total_bytes": 1024,
      "free_bytes": 512,
      "usage_percent": 0.5
    }
  ],
  "errors": [
    {
      "metric": "cpu.temperature",
      "error": "unable to get cpu temperature"
    }
  ]
}