重启Hadoop，报错如下：
Cannot create directory /tmp/hive/root/67ae8485-0e7e-4e31-af1b-276dce2e86d3. Name node is in safe mode.
The reported blocks 70 has reached the threshold 0.9990 of total blocks 70. The minimum number of live datanodes is not required. In safe mode extension. Safe mode will be turned off automatically in 10 seconds.
解决办法：
[root@bigdata hadoop]# $HADOOP_HOME/bin/hadoop dfsadmin -safemode leave
DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.
Safe mode is OFF