我安装了 cloudera vm 并开始尝试一些基本的东西。首先，我只是想 ls hdfs 目录。所以我发出了以下命令。
[cloudera@quickstart ~]$ hadoop fs -ls /
ls: Failed on local exception: java.net.SocketException: Network is unreachable; Host Details : local host is: "quickstart.cloudera/10.0.2.15"; destination host is: "quickstart.cloudera":8020;
虽然 ps -fu hdfs 说名称节点和数据节点都在运行。我使用 service 命令检查了状态。
[cloudera@quickstart ~]$ sudo service hadoop-hdfs-namenode status
Hadoop namenode is not running [FAILED]
认为如果我重新启动所有服务将解决所有问题，我执行了以下命令。
[cloudera@quickstart conf]$ sudo /home/cloudera/cloudera-manager --express --force
[QuickStart] Shutting down CDH services via init scripts...
[QuickStart] Disabling CDH services on boot...
[QuickStart] Starting Cloudera Manager daemons...
[QuickStart] Waiting for Cloudera Manager API...
[QuickStart] Configuring deployment...
Submitted jobs: 92
[QuickStart] Deploying client configuration...
Submitted jobs: 93
[QuickStart] Starting Cloudera Management Service...
Submitted jobs: 101
[QuickStart] Enabling Cloudera Manager daemons on boot...
现在我认为所有服务都会启动，所以再次检查了 namenode 服务的状态。又来了，失败了。
[cloudera@quickstart ~]$ sudo service hadoop-hdfs-namenode status
Hadoop namenode is not running [FAILED]
现在我决定手动停止并启动namenode服务。又没多大用处。
[cloudera@quickstart ~]$ sudo service hadoop-hdfs-namenode stop
no namenode to stop
Stopped Hadoop namenode: [ OK ]
[cloudera@quickstart ~]$ sudo service hadoop-hdfs-namenode status
Hadoop namenode is not running [FAILED]
[cloudera@quickstart ~]$ sudo service hadoop-hdfs-namenode start
starting namenode, logging to /var/log/hadoop-hdfs/hadoop-hdfs-namenode-quickstart.cloudera.out
Failed to start Hadoop namenode. Return value: 1 [FAILED]
我检查了文件 /var/log/hadoop-hdfs/hadoop-hdfs-namenode-quickstart.cloudera.out 。下面就说了
log4j:ERROR Could not find value for key log4j.appender.RFA
log4j:ERROR Could not instantiate appender named "RFA".
我还检查了 /var/log/hadoop-hdfs/hadoop-cmf-hdfs-NAMENODE-quickstart.cloudera.log.out 。当我搜索错误时在下面找到。谁能建议我让服务重回正轨的最佳方法是什么。不幸的是，我无法从浏览器访问 cloudera manager。我可以从命令行做什么？
2016-02-24 21:02:48,105 WARN com.cloudera.cmf.event.publish.EventStorePublisherWithRetry: Failed to publish event: SimpleEvent{attributes={ROLE_TYPE=[NAMENODE], CATEGORY=[LOG_MESSAGE], ROLE=[hdfs-NAMENODE], SEVERITY=[IMPORTANT], SERVICE=[hdfs], HOST_IDS=[quickstart.cloudera], SERVICE_TYPE=[HDFS], LOG_LEVEL=[WARN], HOSTS=[quickstart.cloudera], EVENTCODE=[EV_LOG_EVENT]}, content=Only one image storage directory (dfs.namenode.name.dir) configured. Beware of data loss due to lack of redundant storage directories!, timestamp=1456295437905} - 1 of 17 failure(s) in last 79302s
java.io.IOException: Error connecting to quickstart.cloudera/10.0.2.15:7184
at com.cloudera.cmf.event.shaded.org.apache.avro.ipc.NettyTransceiver.getChannel(NettyTransceiver.java:249)
at com.cloudera.cmf.event.shaded.org.apache.avro.ipc.NettyTransceiver.<init>(NettyTransceiver.java:198)
at com.cloudera.cmf.event.shaded.org.apache.avro.ipc.NettyTransceiver.<init>(NettyTransceiver.java:133)
at com.cloudera.cmf.event.publish.AvroEventStorePublishProxy.checkSpecificRequestor(AvroEventStorePublishProxy.java:122)
at com.cloudera.cmf.event.publish.AvroEventStorePublishProxy.publishEvent(AvroEventStorePublishProxy.java:196)
at com.cloudera.cmf.event.publish.EventStorePublisherWithRetry$PublishEventTask.run(EventStorePublisherWithRetry.java:242)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.SocketException: Network is unreachable