title: How to modify the behaviour of filesystem cache in Mac OS
body: <p>I'm wondering if in MacOS there are parameters equivalent to the Linux ones:</p>
  
  <pre><code>vm.dirty_background_bytes
  vm.dirty_background_ratio
  vm.dirty_bytes
  vm.dirty_ratio
  vm.dirty_expire_centisecs
  vm.dirty_writeback_centisecs
  </code></pre>
  
  <p>By mean of them one can change the behavior of buffer/cache of the filesystem, e.g. how much RAM to use to caching files' blocks, after how much time flush the cache to disk, etc.
  Those parameters, in linux, are modified by the <code>sysctl</code> command. In the MacOS documentation I cannot find equivalent parameters.</p>
  
  <p>Any hint ?</p>
  
  <p>Thanks in advance.</p>