title: Site crashing, Can't create/write to file '/tmp
body: <p>I have a site that is using <code>question2answer</code> script and some custom made code.
  I recently have a problem with the site crashing. The error I get when I open the page is:</p>
  
  <p>Database query error 1
  <code>Can't create/write to file '/tmp/#sql_819_0.MYI' (Errcode: 13)</code></p>
  
  <pre><code>(SELECT 'options' AS selectkey, title, content FROM qa_options) UNION ALL (SELECT 'time', 'db_time', UNIX_TIMESTAMP(NOW()))
  </code></pre>
  
  <p>All seems to be fine with the tmp permissions: <code>drwxrwxrwt</code></p>
  
  <p>I don't know when this is happening. If I restart the server everything is working fine and I get no errors. Then, after some time it is happening again. Site is down and all I get is that message.</p>
  
  <p>Really need your help!</p>