Index: src/java/org/apache/nutch/crawl/CrawlDbMerger.java
===================================================================
--- src/java/org/apache/nutch/crawl/CrawlDbMerger.java	(revision 1543832)
+++ src/java/org/apache/nutch/crawl/CrawlDbMerger.java	(working copy)
@@ -125,6 +125,8 @@
     }
     JobClient.runJob(job);
     FileSystem fs = FileSystem.get(getConf());
+    if(fs.exists(output))
+      fs.delete(output,true);
     fs.mkdirs(output);
     fs.rename(FileOutputFormat.getOutputPath(job), new Path(output, CrawlDb.CURRENT_NAME));
     long end = System.currentTimeMillis();