title: Why fork() twice
body: <p>Nagios lets me configure <code>child_processes_fork_twice=&lt;0/1&gt;</code>.</p>
  
  <p>The <a href="http://nagios.sourceforge.net/docs/nagioscore/3/en/configmain.html#child_processes_fork_twice" rel="noreferrer">documentation</a> says </p>
  
  <blockquote>
    <p>This option determines whether or not Nagios will fork() child processes twice when it executes host and service checks. By default, Nagios fork()s twice. However, if the use_large_installation_tweaks option is enabled, it will only fork() once.</p>
  </blockquote>
  
  <p>As far as I know <code>fork()</code> will spawn a new child process. <em>Why would I want to do that twice?</em>  </p>