@Test
  public void testPersistOverflowASyncWithoutBufferRollOlg9() {
    try {
      // Create four Dirs for Disk Dirs
      File file1 = new File("testPersistOverflowASyncWithoutBufferRollOlg9Dir1");
      file1.mkdir();
      file1.deleteOnExit();
      File file2 = new File("testPersistOverflowASyncWithoutBufferRollOlg9Dir2");
      file2.mkdir();
      file2.deleteOnExit();
      File file3 = new File("testPersistOverflowASyncWithoutBufferRollOlg9Dir3");
      file3.mkdir();
      file3.deleteOnExit();
      File file4 = new File("testPersistOverflowASyncWithoutBufferRollOlg9Dir4");
      file4.mkdir();
      file4.deleteOnExit();
      dirs = new File[4];
      dirs[0] = file1;
      dirs[1] = file2;
      dirs[2] = file3;
      dirs[3] = file4;

      diskProps.setTimeInterval(1000l);
      diskProps.setBytesThreshold(0l);
      diskProps.setRolling(true);
      diskProps.setMaxOplogSize(20971520l);
      diskProps.setOverFlowCapacity(1000);
      region = DiskRegionHelperFactory.getAsyncOverFlowAndPersistRegion(cache, diskProps);
    } catch (Exception e) {
      e.printStackTrace();
      fail("failed in testPersistOverflowASyncWithoutBufferRollOlg9");
    }
    // Perf test for 1kb writes
    if (runPerfTest) {
      populateData0to60k();
      populateData60kto100k();
      System.out.println(
          "Persist-OverflowASyncWITHOUTBufferRollOlg9(with DiskWriteAttributes Time-out of 1 Second):: Stats for 1 kb writes :"
              + stats);
    }
    // Perf test for 1kb writes. Puting values on the same KEY
    /*
     * if(runPerfTest){ populateDataPutOnSameKey();
     * System.out.println("Persist-OverflowASyncWITHOUTBuffer9:: Stats for 1 kb writes :"+
     * stats_ForSameKeyputs); }
     */
    // Deleting all the files and logs created during the test...
    deleteFiles();
    closeDown();
  }
To run DiskRegionRollOpLogPerfJUnitTest to produce the Perf numbers set runPerfTest to true.
Also ,one needs to set the VM heap size accordingly. (For example:Default setting in build.xml
is <jvmarg value="-Xmx256M"/>
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/diskPerf/DiskRegionRollOpLogJUnitPerformanceTest.java