Fix MySQL problem after dist-upgrade

Often after doing dist-upgrade on Ubuntu using a command,

sudo apt-get dist-upgrade

MySQL server fails to start throwing an error message,

sudo service mysql start
error:
start: Job failed to start

Here is a simple solution to above problem.

Create a backup of your existing MySQL

sudo cp -r /var/lib/mysql ~/mysql-backup

Remove existing MySQL package and related files

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

Remove configuration files if any

remove files from /etc/mysql/

sudo rm /etc/mysql/ -R

Restore and fix permissions

After a purge, you can restore back your backup files to /var/lib/mysql if they does not exist.

sudo mkdir /var/lib/mysql
sudo cp -r ~/mysql-backup/* /var/lib/mysql

and fix the permissions.

sudo chown root:root /var/lib/mysql/ -R

Reinstall MySQL

Now reinstall MySQL package.

sudo apt-get install mysql-server

This should fix the problem. Verify it using,

sudo service mysql start