title: How to deal with the amazon ec2's clock drift?
body: <p>We have a couple of ec2 instances on amazon, and we used amazon AIM Linux to set up. The instance type is m1.medium.</p>
  
  <p>Everything is going well until this week.</p>
  
  <p>We found from log file that there would be a huge clock drift happened suddenly, and sometimes there has a 5-minutes discrepancy。</p>
  
  <p>I would like to ask if anyone else encounter this problem? How to deal with it?</p>