启动mysql服务是报错找不到pid_mysql报错 The server quit without updating PID file

我的mysql总是在重启的时候mysql的数据总是会初始化，我以为是的配置问题，所以在网上找了各种方法测试都不通过，下面看我遇到的几个错误。

重启mysql失败

[root@wulaoer_mysql mysql]# /etc/init.d/mysql restart

ERROR! MySQL server PID file could not be found!

Starting MySQL... ERROR! The server quit without updating PID file (/usr/local/mysql/var/wulaoer_mysql.pid).

mysql正常重启的时候突然出现找不到pid文件，解决方法：

[root@wulaoer_mysql mysql]# ps -ef | grep mysql

root 12676 1 0 Dec11 pts/1 00:00:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --datadir=/usr/local/mysql/var --pid-file=/usr/local/mysql/var/wulaoer_mysql.pid

mysql 13193 12676 0 Dec11 pts/1 00:02:58 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/usr/local/mysql/var --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=wulaoer_mysql.err --open-files-limit=65535 --pid-file=/usr/local/mysql/var/wulaoer_mysql.pi