Starting MySQL....The server quit without updating PID file 处理方法

报错：

Starting
MySQL....The server quit without updating PID file ...

查看错误日志

情景1：

120217
15:09:57[ERROR] Can't start server : Bind on unix socket: No such file or directory

120217 15:09:57[ERROR]
Do you already have another mysqld server running on socket: /mysql/mysqldir/data/mysql.sock ?

120217 15:09:57[ERROR]
Aborting

于是ps
-ef | grep mysql 一把.未发现有mysqld.

netstat
-an | grep 3306 一把.也未发现异常.

检查/etc/my.cnf中的socket的配置项，确定mysql.sock的文件位置是否正确。

最后从mysql安装目录下重新复制一个配置文件到/etc/my.cnf

修改相应参数.于是问题解决

情景2：

/mysql/mysqldir/bin/mysqld:
Table 'mysql.plugin' doesn't exist

[ERROR]
Can't open the mysql.plugin table. Please run my sql_upgrade to create it.

原因：编译安装后忘记初始化表.

解决：运行mysql_install_db