Hadoop bin/hadoop namenode -format 时遇到的几个问题

Question 1:

hadoop执行hdfs namenode -format的时候，提示：

错误: 找不到或无法加载主类

 org.apache.hadoop.hdfs.server.namenode.NameNode

Answer 1:

找到​hadoop-config.sh（2.6.0的是在libexec文件夹下）

找到最后一行

if [ "$HADOOP_CLASSPATH" != "" ]; then

  # Prefix it if its to be preceded

  if [ "$HADOOP_USER_CLASSPATH_FIRST" != "" ]; then

    CLASSPATH=${HADOOP_CLASSPATH}:${CLASSPATH}

  else

    CLASSPATH=${CLASSPATH}:${HADOOP_CLASSPATH}

  fi

fi

替换为

CLASSPATH=`cygpath -wp "$CLASSPATH"`

if [ "$HADOOP_CLASSPATH" != "" ]; then

  # Prefix it if its to be preceded

  if [ "$HADOOP_USER_CLASSPATH_FIRST" != "" ]; then

    CLASSPATH=${HADOOP_CLASSPATH}:${CLASSPATH}

  else

    CLASSPATH=${CLASSPATH}:${HADOOP_CLASSPATH}

  fi

fi

 

 

 

 

 

Question 2:

ERROR util.Shell: Failed to locate the winutils binary inthe hadoop binary path

Could not locate executable null\bin\winutils.exe in theHadoop binaries

 

 

Answer 2:

1.下载winutils的windows版本

地址是： https://github.com/srccodes/hadoop-common-2.2.0-bin,下载此zip包，解压后把winutils.exe加入hadoop-x.x.x/bin下
2.配置环境变量

增加用户变量HADOOP_HOME，值是本机的hadoop的路径

 

Question 3:

DEPRECATED: Use of this script to execute hdfs command isdeprecated.

Instead use the hdfs command for it.
Answer 3:

HADOOP_HOME没有设置:
执行：
export HADOOP_HOME="hadoop安装路径"

[b]Question 4:[/b]
HDFS格式化bin/hadoop namenode -format时出现未知主机名错误：java.net.UnknownHostException: localhost.localdomain: localhost.localdomain 
Answer 4:

echo localhost > /proc/sys/kernel/hostname

[b]Question 5:
1.conf文件夹去哪儿了？
2.start-all.sh文件去哪儿了？
[/b]

Answer 5:

hadoop2.6 默认
1.将conf文件夹变更为 $HADOOP_HOME/etc/hadoop/
2.start-all.sh文件在 $HADOOP_HOME/sbin/