```
$hdfs dfs -rmr crawl
    11/04/16 08:49:33 INFO security.Groups: Group mapping impl=org.apache.hadoop.security.ShellBasedUnixGroupsMapping; cacheTimeout=300000

```

I'm using hadoop-0.21.0 with the [default Single Node Setup configuration](http://hadoop.apache.org/common/docs/current/single_node_setup.html#Local).