MySQL Daemon Failed to Start – centos 6

EDIT: Look at the checkmarked answer comments to get your issue solved.

Whenever I try to start the SQLD service I get MySQL Daemon Failed to Start. I infact tried to “start” the service by doing the following:

service mysqld start

Also

When I type: mysql

I get:

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

I know that there should be a mysql.sock file in that directory, so I create one. But the file just auto removes its self and I continue to get the error 2002.

I am also unable to log into PHPMyAdmin due to the error. I can access phpmyadmin page but when logging in I get: #2002 Cannot log in to the MySQL server

EDIT:

Here is my mysql.log file:

131201 13:05:07 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
131201 13:18:18 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
131201 13:18:18 [Note] Plugin 'FEDERATED' is disabled.
/usr/libexec/mysqld: Can't find file: './mysql/plugin.frm' (errno: 13)
131201 13:18:18 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
131201 13:18:18 InnoDB: The InnoDB memory heap is disabled
131201 13:18:18 InnoDB: Mutexes and rw_locks use GCC atomic builtins
131201 13:18:18 InnoDB: Compressed tables use zlib 1.2.3
131201 13:18:18 InnoDB: Using Linux native AIO
131201 13:18:18 InnoDB: Initializing buffer pool, size = 128.0M
131201 13:18:18 InnoDB: Completed initialization of buffer pool
131201 13:18:18  InnoDB: Operating system error number 13 in a file operation.
InnoDB: The error means mysqld does not have the access rights to
InnoDB: the directory.
InnoDB: File name ./ibdata1
InnoDB: File operation call: 'open'.
InnoDB: Cannot continue operation.
131201 13:18:18 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended

I ran mysql_upgrade and got

Looking for 'mysql' as: mysql
Looking for 'mysqlcheck' as: mysqlcheck
FATAL ERROR: Upgrade failed

Answer

The most likely cause for this error is that your mysql server is not running. When you type in mysql you are executing mysql client.

Try:

# sudo service mysql start
# mysql

Update (after OP included log in the question; taken from the comments below):

Thanks, saw your log. The log is saying the mysql user doesn’t have proper access rights. I’m assuming your mysql user is mysql(this can be verified in /etc/my.cnf, execute

chown -R mysql:mysql /var/lib/mysql

and try starting mysqld again.