ERROR! MySQL server PID file could not be found!解决方法

故障现象：
当我们重新启动mysql服务时出现以下报错

[root@cong1 lib]# service mysqld restart    ##重启
 ERROR! MySQL server PID file could not be found!     ##报错

解决方法：
进程占用，查看mysql进程，将显示出来的进程kill掉即可

[root@cong1 lib]# ps aux |grep mysq*    ##查看进程
root      19554  0.0  0.0  11688  1564 pts/0    S    07:44   0:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --datadir=/home/mysql --pid-file=/home/mysql/localhost.localdomain.pid
mysql     19669  0.0 23.8 1036364 445160 pts/0  Sl   07:44   0:04 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/home/mysql --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=/home/mysql/localhost.localdomain.err --pid-file=/home/mysql/localhost.localdomain.pid
root      23735  0.0  0.0 112728   976 pts/0    R+   09:44   0:00 grep --color=auto mysq*
[root@cong1 lib]# kill 19554
[root@cong1 lib]# kill 19669
[root@cong1 lib]# kill 23753
bash: kill: (23753) - 没有那个进程
[root@cong1 lib]# service mysqld restart
 ERROR! MySQL server PID file could not be found!
Starting MySQL.. SUCCESS!   ###成功