I restarted mysqld from WHM/cPanel and result was:

mysql has failed, please contact the sysadmin (result was "mysql is not running")
In my case this was result of my recent editation in /etc/my.cnf file. I just opened the file and deleted lines i added. Saved and did:

service mysql start ... and mysql started, OK.


Another advices:

Code:
service mysql stop
show mysql processes
Code:
ps aux | grep mysql
then:
Code:
kill processid
or kill all mysql:
Code:
pkill -f mysql
or check /var/run for mysql .pid and remove it
Code:
ls -l /var/run | grep mys
Code:
rm filename
try start mysql again:
Code:
service mysql start
error logs:
Code:
tail -n30 /var/log/mysql*
Submit ticket to cPanel and ask at cPanel forums (in case you are using WHM/cpanel)