登录服务器，使用root用户连接mysql时出现错误提示：
$ bin/mysql -uroot -pEnter password: ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)
尝试重启mysql
$ ./mysql.server restartShutting down MySQL (Percona Server)....... [ OK ]rm: cannot remove `/var/lock/subsys/mysql': Permission deniedStarting MySQL (Percona Server).. [ OK ][mysql@tongxtx mysql]$ bin/mysql -uroot -pEnter password: ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)
还是报同样的错。先看一下my.cnf
more my.cnf |grep socksocket = /opt/mysql/mysql.socksocket = /opt/mysql/mysql.sock
可以看到我的mysql已经声明了mysql.sock的文件位置，而错误提示为/tmp/mysql.sock; 也就是说虽然我的mysql声明了sock文件的位置，但是客户端在连接的时候, linux系统总是去/tmp目录下去找，找到了原因，就可以对症下药了：
为mysql.sock创建链接文件：
$ ln -s /opt/mysql/mysql.sock /tmp/mysql.sock