title: Difference between 'distcp' and 'distcp -update'?
body: <p>What is the difference between</p>
  
  <pre><code>hadoop distcp
  </code></pre>
  
  <p>and </p>
  
  <pre><code>hadoop distcp -update
  </code></pre>
  
  <p>Both of them would do the same work with only slight difference in how we call them. None of them overwrites an already existing file in the destination. What's the point then in two different set of commands?</p>