mysql中pid文件丢失怎么办

mysql> show variables like 'pid_file';
+---------------+--------------------------------+
| Variable_name | Value                          |
+---------------+--------------------------------+
| pid_file      | /opt/mysql/data/gfsunny105.pid |
+---------------+--------------------------------+
1 row in set (0.02 sec)
[root@gfsunny105 data]# cat gfsunny105.pid
4466

[root@gfsunny105 data]# mv gfsunny105.pid gfsunny105.pid_bak

[root@gfsunny105 data]# service mysqld stop
MySQL server PID file could not be found!                  [FAILED]

[root@gfsunny105 data]# service mysqld stop
Shutting down MySQL...                                     [  OK  ]
[root@gfsunny105 data]# service mysqld start
Starting MySQL.......                                      [  OK  ]