error: 'Can't connect to local MySQL server

error: 'Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)'，connectmysql.sock

 [root@luozhonghua ~]#   /usr/bin/mysqladmin -u root password 'aaaaaa'
/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!
解决：
1》/etc/rc.d/init.d/mysqld status 看看mysql是否已经启动
2》service mysqld start

1、先查看 /etc/rc.d/init.d/mysqld status 看看m y s q l 是否已经启动.
另外看看是不是权限问题.
2、确定你的mysql.sock是不是在那个位置，
mysql -u 你的mysql用户名 -p -S /var/lib/mysql/mysql.sock
3、试试：service mysqld start
 

/etc/my.cnf这个文件不对，需要重新创建一个，步骤如下：
cd mysql-VERSION 到解压缩文件的目录下
复制
cp support-files/my-medium.cnf /etc/my.cnf
重新初始化，创建授权表
bin/mysql_install_db --user=mysql

启动服务
bin/mysqld_safe --user=mysql &