linux下自己创建/etc/my.cnf文件导致启动mysql时报错：

Starting MySQL........ ERROR! The server quit without updating PID file (/var/lib/mysql/mini1.pid).

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过程：rpm方式安装mysql5.6没有配置文件/etc/my.cnf
于是自己拷了一份其他linux上的配置文件(已配置好双主，其中修改了默认编码为utf8，部分配置如下：)

[mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock collation_server = utf8_general_ci                      # collation 比对方法 character_set_server = utf8 rpl_semi_sync_slave_enabled=1

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登陆mysql，show variables like“character%”;
发现server端编码仍为latin1

| character_set_database   | latin1                     |
| character_set_server     | latin1 

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检查发现新建配置文件后未重启mysql服务，于是重启。service mysql restart 报错：

Shutting down MySQL.. SUCCESS!
Starting MySQL........ ERROR! The server quit without updating PID file (/var/lib/mysql/mini1.pid).

==

查看日志：

[root@mini1 scripts]# tail -20 /var/log/mysqld.log
2017-08-06 09:25:56 1649 [Note] InnoDB: Starting shutdown...
2017-08-06 09:25:58 1649 [Note] InnoDB: Shutdown completed; log sequence number 1630108
2017-08-06 09:25:58 1649 [Note] Shutting down plugin 'PERFORMANCE_SCHEMA'
2017-08-06 09:25:58 1649 [Note] Shutting down plugin 'BLACKHOLE'
2017-08-06 09:25:58 1649 [Note] Shutting down plugin 'ARCHIVE'
2017-08-06 09:25:58 1649 [Note] Shutting down plugin 'CSV'
2017-08-06 09:25:58 1649 [Note] Shutting down plugin 'MEMORY'
2017-08-06 09:25:58 1649 [Note] Shutting down plugin 'MRG_MYISAM'
2017-08-06 09:25:58 1649 [Note] Shutting down plugin 'MyISAM'
2017-08-06 09:25:58 1649 [Note] Shutting down plugin 'sha256_password'
2017-08-06 09:25:58 1649 [Note] Shutting down plugin 'mysql_old_password'
2017-08-06 09:25:58 1649 [Note] Shutting down plugin 'mysql_native_password'
2017-08-06 09:25:58 1649 [Note] Shutting down plugin 'binlog'
2017-08-06 09:25:58 1649 [Note] /usr/sbin/mysqld: Shutdown complete
 
170806 09:25:58 mysqld_safe mysqld from pid file /var/lib/mysql/mini1.pid ended

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杀死进程，重启服务，仍然报错。

[root@mini1 scripts]# pkill mini1
[root@mini1 scripts]# service mysql status
 ERROR! MySQL is not running, but lock file (/var/lock/subsys/mysql) exists
[root@mini1 scripts]# rm -rf /var/lock/subsys/mysql
[root@mini1 scripts]# service mysql start
Starting MySQL........ ERROR! The server quit without updating PID file (/var/lib/mysql/mini1.pid).

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最后没办法-->>>度娘

1.检查/var/lib下的mysql文件夹所属用户及组皆为mysql
2.ps -ef|grep mysql杀死进程。
3.如果是二次安装，删除数据库目录/data下的mysql-bin.index。
4.[mysqld]下指定datadir=/var/lib/mysql
5.检查my.cnf文件中如果有skip-federated字段将其注释掉
6.配置的错误日志目录是否存在，授权为mysql所有者权限
7.将/etc/selinux/config中的SELINUX=enforcing改为SELINUX=disabled

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上述依次检查修改完毕，错误依旧。

继续百度，参考文章：http://blog.csdn.net/apple9005/article/details/72420402  

[root@mini1 scripts]# rpm -qa | grep mariadb# MariaDB数据库管理系统是MySQL的一个分支。如果有，全部卸载。我这里没有。
[root@mini1 scripts]# cd /var/lib/mysql
[root@mini1 mysql]# less mini1.err
[root@mini1 mysql]# yum -y install autoconf
[root@mini1 mysql]# /usr/bin/mysql_install_db -user=mysql

报错：	2017-08-06 09:46:13 2890 [ERROR] /usr/sbin/mysqld: unknown variable 'rpl_semi_sync_slave_enabled=1'
2017-08-06 09:46:13 2890 [ERROR] Aborting
删除my.cnf文件中rpl_semi_sync_slave_enabled=1后，继续执行/usr/bin/mysql_install_db -user=mysql
显示一堆刚安装mysql时修改密码之类的提示信息，
……
PLEASE REMEMBER TO SET A PASSWORD FOR THE MySQL root USER !
To do so, start the server, then issue the following commands:

/usr/bin/mysqladmin -u root password 'new-password'
/usr/bin/mysqladmin -u root -h mini1 password 'new-password'
……

===========================>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

到此，The server quit without updating PID file问题成功解决。

但此时启动mysql，报了另外一个错：
[root@mini1 mysql]# mysql -uroot -proot
Warning: Using a password on the command line interface can be insecure.
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
直接删除/var/lib/mysql/mysql.sock无效。意识到应该是密码错误的问题，以为是重新配置了mysql导致密码需要重新配置，于是使用刚刚提示的mysqladmin修改密码，然而也不行。
[root@mini1 mysql]# /usr/bin/mysqladmin -u root password 'root'
/usr/bin/mysqladmin: connect to server at 'localhost' failed
error: 'Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)'
Check that mysqld is running and that the socket: '/var/lib/mysql/mysql.sock' exists!

查看之前收藏过的文章：http://www.360doc.com/content/17/0726/03/44201090_674155868.shtml 

检查发现由于mysql服务未启动导致。。。
[root@mini1 mysql]# service mysql status
 ERROR! MySQL is not running, but lock file (/var/lock/subsys/mysql) exists
[root@mini1 mysql]# rm -rf /var/lock/subsys/mysql
[root@mini1 mysql]# service mysql start
Starting MySQL........ SUCCESS!
[root@mini1 mysql]# mysql -uroot -proot
成功登陆mysql，查看编码字符集设置，也全为utf-8！说明已读取了自己配置的/etc/my.cnf文件, 问题解决！