ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

OS is Red Hat Enterprise Linux Server 6.2

Problem:

# mysql
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

Solution:

Check 1: Make sure you have installed mysql-server NOT just mysql client! :
# yum install mysql
# yum install mysql-server

Check 2: Make sure mysqld is running, if not! start it:

# ps -ef | grep mysqld
root      3451     1  0 18:15 pts/1    00:00:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --socket=/var/lib/mysql/mysql.sock --pid-file=/var/run/mysqld/mysqld.pid --basedir=/usr --user=mysql
mysql     3540  3451  0 18:15 pts/1    00:00:00 /usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/var/log/mysqld.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock
root      3576  3252  0 18:21 pts/1    00:00:00 grep mysqld

# /etc/init.d/mysqld start

Problem Solved:

# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.1.52 Source distribution

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