title: Data loss after repair
body: <p>Our repair jobs failed for a long period (> 14 days).
  Today i manually started an repair job with <code>nodetool repair -pr</code>. Afterwards it looks like we lost some data from a table. </p>
  
  <p>Question:
  Is it theoretically possible to lose data after a repair job?
  If yes what can be done to avoid this?</p>