title: Elastic Search: Correct way to restart a cluster without unassigned shards issue
body: <p>I have a 4 nodes &amp; 5 shards Elastic Search (0.90.3) cluster. On restart, I see 4 of 5 shards unassigned and cluster status is red. So I am assuming the way it was restarted was not right. Each node was issued a kill (SIGKILL) command in 30 seconds interval. Meaning some node was killed, 30 seconds later some other node from the remaining 3 was killed &amp; so on.</p>
  
  <p>I tried <a href="https://stackoverflow.com/questions/19967472/elasticsearch-unassigned-shards-how-to-fix">this</a> solution to have shards reassigned but nothing worked until I manual assigned a primary shard to the cluster using <a href="http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/cluster-reroute.html" rel="nofollow noreferrer">this</a> approach. But manual assigning of primary shard resets the data for the shard resulting in loss. </p>
  
  <p>How do I avoid getting into the unassigned shard problem? And If I am stuck with that problem what is the way to recover without data loss?</p>