title: Can not start Cassandra 2.0 on Ubuntu 13.04 "upgrade to 1.2.5+ first"
body: <p>I tried to install Cassandra 2.0 on my Ubuntu 13.04, but I'm getting this error when i try to start it:</p>
  
  <pre><code>java.lang.UnsupportedOperationException: Commitlog segment is too old to open; upgrade to 1.2.5+ first
      at org.apache.cassandra.db.commitlog.CommitLogDescriptor.fromFileName(CommitLogDescriptor.java:65)
      at org.apache.cassandra.db.commitlog.CommitLogSegment$CommitLogSegmentFileComparator.compare(CommitLogSegment.java:391)
      at org.apache.cassandra.db.commitlog.CommitLogSegment$CommitLogSegmentFileComparator.compare(CommitLogSegment.java:386)
      at java.util.TimSort.countRunAndMakeAscending(TimSort.java:324)
      at java.util.TimSort.sort(TimSort.java:189)
      at java.util.TimSort.sort(TimSort.java:173)
      at java.util.Arrays.sort(Arrays.java:659)
      at org.apache.cassandra.db.commitlog.CommitLog.recover(CommitLog.java:124)
      at org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:300)
      at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:443)
  at org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:486)
  </code></pre>
  
  <p>Can anybody help me?</p>