啓動hdfs失敗：
查看日誌文件：
/var/log/hadoop-hdfs
tail -f hadoop-cmf-hdfs-NAMENODE-XXXX.log.out2018-06-15 17:20:50,996 INFO org.mortbay.log: Stopped HttpServer2$SelectChannelConnectorWithSafeStartup@bj-esbp-master.w-oasis.com:50070
2018-06-15 17:20:51,096 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Stopping NameNode metrics system...
2018-06-15 17:20:51,096 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: NameNode metrics system stopped.
2018-06-15 17:20:51,097 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: NameNode metrics system shutdown complete.
2018-06-15 17:20:51,097 ERROR org.apache.hadoop.hdfs.server.namenode.NameNode: Failed to start namenode.
org.apache.hadoop.hdfs.server.common.InconsistentFSStateException: Directory /data/dfs/nn is in an inconsistent state: storage directory does not exist or is not accessible.
at org.apache.hadoop.hdfs.server.namenode.FSImage.recoverStorageDirs(FSImage.java:325)
at org.apache.hadoop.hdfs.server.namenode.FSImage.recoverTransitionRead(FSImage.java:213)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFSImage(FSNamesystem.java:1081)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFromDisk(FSNamesystem.java:778)
at org.apache.hadoop.hdfs.server.namenode.NameNode.loadNamesystem(NameNode.java:614)
at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:676)
at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:844)
at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:823)
at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1548)
at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1616)
2018-06-15 17:20:51,098 INFO org.apache.hadoop.util.ExitUtil: Exiting with status 1
2018-06-15 17:20:51,099 INFO org.apache.hadoop.hdfs.server.namenode.NameNode: SHUTDOWN_MSG: