[hadoop@zui hadoop]$ hadoop namenode -format
WARNING: Use of this script to execute namenode is deprecated.
WARNING: Attempting to execute replacement "hdfs namenode" instead.
namenode is running as process 18452. Stop it first.
(3.0.3使用 ： hdfs namenode -formate)
[hadoop@zui hadoop]$ stop-dfs.sh
Stopping namenodes on [zui]
zui: Warning: Permanently added 'zui' (ECDSA) to the list of known hosts.
zui: ERROR: Unable to kill 18452
Stopping datanodes
localhost: ERROR: Unable to kill 19132
Stopping secondary namenodes [zui]
zui: ERROR: Unable to kill 19311
[hadoop@zui hadoop]$ stop-all.sh
WARNING: Stopping all Apache Hadoop daemons as hadoop in 10 seconds.
WARNING: Use CTRL-C to abort.
Stopping namenodes on [zui]
zui: ERROR: Unable to kill 18452
Stopping datanodes
localhost: ERROR: Unable to kill 19132
Stopping secondary namenodes [zui]
zui: ERROR: Unable to kill 19311
Stopping nodemanagers
Stopping resourcemanager
[hadoop@zui hadoop]$ hdfs namenode -format
namenode is running as process 18452. Stop it first.
[hadoop@zui hadoop]$ kill -9 18452
bash: kill: (18452) - No such process
[hadoop@zui hadoop]$ sudo kill -9 18452
[sudo] password for hadoop:
hadoop is not in the sudoers file. This incident will be reported.
(使用root kill 进程)
[hadoop@zui hadoop]$ su root
Password:
[root@zui hadoop]# kill -9 18452
bash: kill: (18452) - No such process
[root@zui hadoop]# sudo kill -9 18452
kill: sending signal to 18452 failed: No such process
[root@zui hadoop]#
（该进程是否只有在hadoop同户下才可以查到，但是hadoop使用也显示没有这个进程，加上sudo提示hadoop not in the sudoers file )