title: Change owner of the root folder and subfolders (Ubuntu 13.04)
body: <p>I accidentally set owner of root folder (/) and all subfolders to one user by command</p>
  
  <pre><code>$ sudo chown -R 'userName' /*
  </code></pre>
  
  <p>Now I wanna set owner back to root user by command</p>
  
  <pre><code>$ chown -R root:root /*
  </code></pre>
  
  <p>But I have no permission for this operation.
  If i use command</p>
  
  <pre><code>$ sudo chown -R root:root /*
  </code></pre>
  
  <p>it returns </p>
  
  <pre><code> sudo: effective uid is not 0, is sudo installed setuid root?
  </code></pre>
  
  <p>What should I do to fix that?</p>