MySQL Job failed to start

Question

I'm on Kubuntu 12.04, and after installing mysql via an apt-get (mysql ver: 5.5.35), i'm trying to start mysql service, but I got this error:

sudo service mysql start

start: Job failed to start

So I googled this problem, it says i have to go to the /var/log/mysql/error.log

But my error.log file is empty :(

Then I checked the permissions :

drwxr-s--- 2 mysql adm 4096 Apr 7 11:21 mysql

-rw-r----- 1 mysql adm 0 Apr 7 11:21 error.log

So I don't know what to do... Why this error ? Why is the error file empty ?

Answer 1

First make a backup of your /var/lib/mysql/ directory just to be safe.

sudo mkdir /home/<your username>/mysql/
cd /var/lib/mysql/
sudo cp * /home/<your username>/mysql/ -R

Next purge MySQL (this will remove php5-mysql and phpmyadmin as well as a number of other libraries so be prepared to re-install some items after this.

sudo apt-get purge mysql-server-5.1 mysql-common

Remove the folder /etc/mysql/ and it's contents

sudo rm /etc/mysql/ -R

Next check that your old database files are still in /var/lib/mysql/ if they are not then copy them back in to the folder then chown root:root

(only run these if the files are no longer there)

sudo mkdir /var/lib/mysql/
sudo chown root:root /var/lib/mysql/ -R
cd ~/mysql/
sudo cp * /var/lib/mysql/ -R

Next install mysql server

sudo apt-get install mysql-server

Finally re-install any missing packages like phpmyadmin and php5-mysql.