MySQL is running but PID file could not be found(解决方法)

启动MySQL时报错：

[root@xzw /]# service mysqld status

MySQL is running but PID file could not be found    [失败]

解决办法：

找到并kill掉所有关于mysql的进程

ps -ef  | grep mysql

kill 进程号

再次验证，解决！