anchor.diff:  
   `cluster.routing.allocation.disk.watermark.low`::
   
  -    Controls the low watermark for disk usage. It defaults to 85%, meaning ES will
  -    not allocate new shards to nodes once they have more than 85% disk used. It
  -    can also be set to an absolute byte value (like 500mb) to prevent ES from
  -    allocating shards if less than the configured amount of space is available.
  +    Controls the low watermark for disk usage. It defaults to `85%`, meaning
  +    that Elasticsearch will not allocate shards to nodes that have more than
  +    85% disk used. It can also be set to an absolute byte value (like `500mb`)
  +    to prevent Elasticsearch from allocating shards if less than the specified
  +    amount of space is available. This setting has no effect on the primary
  +    shards of newly-created indices or, specifically, any shards that have
  +    never previously been allocated.
   
   `cluster.routing.allocation.disk.watermark.high`::
   
  -    Controls the high watermark. It defaults to 90%, meaning ES will attempt to
  -    relocate shards to another node if the node disk usage rises above 90%. It can
  -    also be set to an absolute byte value (similar to the low watermark) to
  -    relocate shards once less than the configured amount of space is available on
  -    the node.
  +    Controls the high watermark. It defaults to `90%`, meaning that
  +    Elasticsearch will attempt to relocate shards away from a node whose disk
  +    usage is above 90%. It can also be set to an absolute byte value (similarly
  +    to the low watermark) to relocate shards away from a node if it has less
  +    than the specified amount of free space. This setting affects the
  +    allocation of all shards, whether previously allocated or not.
   
   `cluster.routing.allocation.disk.watermark.flood_stage`::
   +
   --
  -Controls the flood stage watermark. It defaults to 95%, meaning ES enforces
  -a read-only index block (`index.blocks.read_only_allow_delete`) on every
  -index that has one or more shards allocated on the node that has at least
  -one disk exceeding the flood stage.  This is a last resort to prevent nodes
  -from running out of disk space.  The index block must be released manually
  -once there is enough disk space available to allow indexing operations to
  -continue.
  +Controls the flood stage watermark. It defaults to 95%, meaning that
  +Elasticsearch enforces a read-only index block
  +(`index.blocks.read_only_allow_delete`) on every index that has one or more
  +shards allocated on the node that has at least one disk exceeding the flood
  +stage. This is a last resort to prevent nodes from running out of disk space.
  +The index block must be released manually once there is enough disk space
  +available to allow indexing operations to continue.
   
   NOTE: You can not mix the usage of percentage values and byte values within
   these settings. Either all are set to percentage values, or all are set to byte
  
positive.code: `cluster.routing.allocation.disk.include_relocations`::
  
      Defaults to +true+, which means that Elasticsearch will take into account
      shards that are currently being relocated to the target node when computing a
      node's disk usage. Taking relocating shards' sizes into account may, however,
      mean that the disk usage for a node is incorrectly estimated on the high side,
      since the relocation could be 90% complete and a recently retrieved disk usage
      would include the total size of the relocating shard as well as the space
      already used by the running relocation.
  
  
  NOTE: Percentage values refer to used disk space, while byte values refer to
  
negative.code: [[disk-allocator]]
  === Disk-based Shard Allocation
  
  Elasticsearch considers the available disk space on a node before deciding
  whether to allocate new shards to that node or to actively relocate shards away
  from that node.
  
  Below are the settings that can be configured in the `elasticsearch.yml` config
  file or updated dynamically on a live cluster with the
  