title: Do not see Spark RDDs after persist
body: <p>I'm using Spark 1.2.0 and haven't configured SPARK_LOCAL_DIRS explicitly so assuming that persisted RDDs would go to /tmp. I'm trying to persist and RDD using the following code:</p>
  
  <pre><code>    val inputRDD=sc.parallelize(List(1,2,3,3,4,5,6,7,8,9,19,22,21,25,34,56,4,32,56,70))
      val result = inputRDD.map(x=&gt;x*x)
      println("Result count is: "+result.count())
      result.persist(StorageLevel.DISK_ONLY)
      println(result.collect().mkString(",,"))
      println("Result count is: "+result.count()) 
  </code></pre>
  
  <p>I force a count() on my RDD before and after persist just to be sure but i still don't see any new files or directories in /tmp. The only directory that changes when i run my code is hsperfdata.... which i know is for JVM perf data. </p>
  
  <p>Where are my persisted RDDs going?</p>