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
drwxr-s--- 2 mysql adm 4096 Apr 7 11:21 mysql
-rw-r----- 1 mysql adm 0 Apr 7 11:21 error.log
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.