Buen tarde, esto iniciando el ejercicio del modulo 1 con hadoop en la maquina virtual, pero al intentar ejecutar el comando hadoop fs -ls / aparece el siguiente error, que puedo hacer ahi?.

Gracias

[cloudera@quickstart ~]$ hadoop fs -ls /
20/05/04 11:36:40 WARN ipc.Client: Failed to connect to server: quickstart.cloudera/127.0.0.1:8020: try once and fail.
java.net.ConnectException: Connection refused
        at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
        at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:739)
        at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
        at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:530)
        at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:494)
        at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:648)
        at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:744)
        at org.apache.hadoop.ipc.Client$Connection.access$3000(Client.java:396)
        at org.apache.hadoop.ipc.Client.getConnection(Client.java:1557)
        at org.apache.hadoop.ipc.Client.call(Client.java:1480)
        at org.apache.hadoop.ipc.Client.call(Client.java:1441)
        at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:230)
        at com.sun.proxy.$Proxy16.getFileInfo(Unknown Source)
        at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:786)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:260)
        at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:104)
        at com.sun.proxy.$Proxy17.getFileInfo(Unknown Source)
        at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:2131)
        at org.apache.hadoop.hdfs.DistributedFileSystem$20.doCall(DistributedFileSystem.java:1265)
        at org.apache.hadoop.hdfs.DistributedFileSystem$20.doCall(DistributedFileSystem.java:1261)
        at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
        at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1261)
        at org.apache.hadoop.fs.Globber.getFileStatus(Globber.java:64)
        at org.apache.hadoop.fs.Globber.doGlob(Globber.java:285)
        at org.apache.hadoop.fs.Globber.glob(Globber.java:151)
        at org.apache.hadoop.fs.FileSystem.globStatus(FileSystem.java:1715)
        at org.apache.hadoop.fs.shell.PathData.expandAsGlob(PathData.java:326)
        at org.apache.hadoop.fs.shell.Command.expandArgument(Command.java:235)
        at org.apache.hadoop.fs.shell.Command.expandArguments(Command.java:218)
        at org.apache.hadoop.fs.shell.FsCommand.processRawArguments(FsCommand.java:102)
        at org.apache.hadoop.fs.shell.Command.run(Command.java:165)
        at org.apache.hadoop.fs.FsShell.run(FsShell.java:315)
        at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
        at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:84)
        at org.apache.hadoop.fs.FsShell.main(FsShell.java:372)
ls: Call From quickstart.cloudera/127.0.0.1 to quickstart.cloudera:8020 failed on connection exception: java.net.ConnectException: Connection refused; For more details see:  http://wiki.apache.org/hadoop/ConnectionRefused