anchor.diff:  `fs.io_stats.write_kilobytes` (Linux only)::
       The total number of kilobytes written across all devices used by {es} since 
       starting {es}.
  +
  +
  +[[cluster-nodes-stats-api-response-body-os]]
  +===== `os` section
   
   The `os` flag can be set to retrieve statistics that concern
   the operating system:
  
positive.code: # Some groups from just the indices stats
  GET /_nodes/stats/indices?groups=foo,bar
  --------------------------------------------------
  
negative.code: [[cluster-nodes-stats-api-response-body]]
  ==== {api-response-body-title}
  
  [[cluster-nodes-stats-api-response-body-fs]]
  ===== `fs` section
  
  The `fs` flag can be set to retrieve information that concern the file system:
  
  `fs.timestamp`::
  