Rhadoop 报Please set an HDFS temp directory with rmr.options

在用Rhadoop运行mapreduce时报以下错误
> small.ints = to.dfs(1:10)
14/04/03 09:51:28 INFO util.NativeCodeLoader: Loaded the native-hadoop library
14/04/03 09:51:28 INFO zlib.ZlibFactory: Successfully loaded & initialized native-zlib library
14/04/03 09:51:28 INFO compress.CodecPool: Got brand-new compressor
Warning messages:
1: In rmr.options("backend") :
  Please set an HDFS temp directory with rmr.options(hdfs.tempdir = ...)
2: In rmr.options("hdfs.tempdir") :
  Please set an HDFS temp directory with rmr.options(hdfs.tempdir = ...)
3: In rmr.options("backend") :
  Please set an HDFS temp directory with rmr.options(hdfs.tempdir = ...)
> 

解决方法：指定hadoop tmp目录也就是hadoop.tmp.dir 参数指定的目录
rmr.options(hdfs.tempdir ='/export/hadoop/tmp')