https://on.spiceworks.com/tickets/open/353/activity

Magneto Database Server is not accessible due to permission problem: chown - R mysql:mysql /data/mysql...

the files IN /var/lib/mysql should be 660.
/var/lib/mysql should be 755.
Any of its subdirectories should be 700.

===========
service mysqld start
service mysqld stop
service mysqld restart

ls -laR /var/lib/mysql
restorecon -r /var/lib/mysql
chmod 755 /var/lib/mysql
sudo chown -R mysql:root folder
cat /etc/passwd


*chown -r mysql:mysql /var/lib/mysql
*Another volume ibig mong sabihin? Tapos chmod -r 750 /var/lib/mysql
chown -R mysql:mysql /var/lib/mysql
chmod -R 750 /var/lib/mysql
===

  [9 Dec 2013 5:58] Kevin Kells
On the other hand, here is a scenario where MySQL 5.1.71 does not shut down gracefully under a CentOS 6.5 reboot, leaving the old /var/lib/mysql/mysql.sock such that mysqld will not start up. I am consistently able to reproduce this error on a CentOS 6.5 KVM guest virtual system by rebooting the host CentOS 6.5 system. CentOS is supposed to gracefully shut down the guest systems, but this seems to be failing in the case of mysqld. Since the reboot of the guest virtual system itself does not trigger the problem, I speculate it's probably more a CentOS 6.5 error than a MySQL error. Thanks, Kevin
[10 Dec 2013 18:25] Sinisa Milivojevic
Actually, MySQL requires to be shutdown properly and both Red Hat and CentOS do not do it correctly. You will always have problems with MySQL if user under whose uid MySQL is running does not have sufficient privileges on all of it's directories, including tmpdir.
[19 Dec 2013 7:24] Fannuel Wamambo
Thanks guys. I was able to overcome this by deleting the /var/lib/mysql/mysql.sock file and changing /tmp permissions to 777 recursively. After a reboot, mysql was running properly. Once again thanks.