title: Unable to start zookeeper services exiting with "Severe unrecoverable error"
body: <p>I'm unable to start zookeeper services. Please see the stack traces. </p>
  
  <ul>
  <li><p><strong>Trace 1 :</strong> org.apache.zookeeper.server.ZooKeeperServer:</p>
  
  <pre><code>Severe unrecoverable error, exiting
  java.io.FileNotFoundException: /var/lib/zookeeper/version-2/snapshot.40003a3c3 (Permission denied)
    at java.io.FileOutputStream.open(Native Method)
    at java.io.FileOutputStream.&lt;init&gt;(FileOutputStream.java:221)
    at java.io.FileOutputStream.&lt;init&gt;(FileOutputStream.java:171)
    at org.apache.zookeeper.server.persistence.FileSnap.serialize(FileSnap.java:225)
    at org.apache.zookeeper.server.persistence.FileTxnSnapLog.save(FileTxnSnapLog.java:275)
    at org.apache.zookeeper.server.ZooKeeperServer.takeSnapshot(ZooKeeperServer.java:270)
    at org.apache.zookeeper.server.SyncRequestProcessor$1.run(SyncRequestProcessor.java:123)
  </code></pre></li>
  <li><p><strong>Trace 2:</strong> org.apache.zookeeper.server.SyncRequestProcessor:</p>
  
  <pre><code>Severe unrecoverable error, exiting
  java.io.FileNotFoundException: /var/lib/zookeeper/version-2/log.40003a3c5 (Permission denied)
    at java.io.FileOutputStream.open(Native Method)
    at java.io.FileOutputStream.&lt;init&gt;(FileOutputStream.java:221)
    at java.io.FileOutputStream.&lt;init&gt;(FileOutputStream.java:171)
    at org.apache.zookeeper.server.persistence.FileTxnLog.append(FileTxnLog.java:205)
    at org.apache.zookeeper.server.persistence.FileTxnSnapLog.append(FileTxnSnapLog.java:347)
    at org.apache.zookeeper.server.ZKDatabase.append(ZKDatabase.java:476)
    at org.apache.zookeeper.server.SyncRequestProcessor.run(SyncRequestProcessor.java:110)
  </code></pre></li>
  </ul>
  
  <p>I've tried - </p>
  
  <ol>
  <li>Changing ownership to zookeeper:zookeeper.</li>
  <li>Changing permission level to 755 and at last 777 for <code>/var/lib/zookeeper</code>. </li>
  <li>Override default dataLogDir and dataDir to <code>/var/lib/zookeeper2</code></li>
  <li>Removing the zookeeper role services from the server and adding back again. </li>
  <li>Decommissioning of full server and added again in the cluster server. </li>
  </ol>