Linux Ubuntu change datadir / database location dir in 5 minutes Move mysql database to other path

Open the terminal
Stop MySQL with the command

• /etc/init.d/mysql stop

Move existing data directory (which is located in /var/lib/mysql) to new dir /usr/new_datadir using the command

• mv /var/lib/mysql /usr/new_datadir

Create symlink from new dir to old one

• ln -s /usr/new_datadir /var/lib/mysql

Don’t change /etc/mysql/my.cnf 
Ubuntu uses some security software called AppArmor that specifies the areas of your filesystem applications are allowed to access. Unless you modify the AppArmor profile for MySQL, you’ll never be able to restart MySQL with the new datadir location.
In the terminal, enter the command

• vim /etc/apparmor.d/usr.sbin.mysqld

Duplicate the lines beginning with /var/lib/mysql and replace duplicated strings with /usr/new_datadir
In my case it was:
………

• /var/lib/mysql/ r,
• /var/lib/mysql/** rwk,
• /var/log/mysql/ r,
• /var/log/mysql/* rw,

• /usr/new_datadir r,
• /usr/new_datadir** rwk,
• /usr/new_datadir r,
• /usr/new_datadir* rw,

……..
Restart the AppArmor profiles with the command

• /etc/init.d/apparmor restart

Restart MySQL with the command

• /etc/init.d/mysql restart

MySQL should now start without any errors, have fun! See also article How to move the mysql datadir, Ubuntu change datadir issue