Fix : ERROR! MySQL server PID file could not be found!

[NickTheGreek 160]

This is a common problem and may have several reasons. Sometimes when we simply want to restart the MySQL Server, we can get such an error:
ERROR! MySQL server PID file could not be found!

First of all, always check if the /tmp partition is full. This can happen when MySQL can’t write to the /tmp partition to create a lock file.

df -h

Also, this may be because, somehow the /tmp partition has been cleared and the MySQL server is looking for the PID file there. So easy-peasy just create a new pid file and restart the server.

touch /tmp/mysql.sock
service mysqld restart

It can also help to check the status, sometimes it helps. For example sometimes you can get an error like this :

$ service mysqld status
ERROR! MySQL is not running, but lock file (/var/lock/subsys/mysql) exists

Well, it’s kind of obvious, just remove the lock file and restart the server.

rm /var/lock/subsys/mysql
service mysqld restart

If this not work then you need to kill current mysql process from server using below steps :

ps -aufx | grep mysql

You get all process of mysql with process ID. You need to kill all PID for mysql using below command

kill -9 PID1 PD2...

then restart mysql service

service mysql restart

That’s it

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