Hadoop cluster restarts safely

1. master node

cd /opt/bigdata/hadoop/hadoop-3.2.0/sbin

./stop-all.sh

2. Then all three nodes

cd /opt/bigdata/hadoop
rm -rf dfs/*
mkdir -p dfs/data 
mkdir -p dfs/name

cd /opt/bigdata/hadoop/hadoop-3.2.0/etc/hadoop

vi yarn-site.xml

加入下面配置：

	<property>
    		<name>yarn.nodemanager.pmem-check-enabled</name>
    		<value>false</value>
	</property>
	<property>
		<name>yarn.nodemanager.vmem-check-enabled</name>
    		<value>false</value>
	</property>

3. master

hadoop namnode -format 

cd /opt/bigdata/hadoop/hadoop-3.2.0/sbin

./start-all.sh