MySQL Issues When Moving DB

On Dabian/Ubuntu systems a few things meed to be done when moving you DB to a location other than /var/lib/mysql.

Edit Apparmor Config

You need to edit the /etc/apparmor.d/usr.sbin.mysqld file.

Look for lines in this file like the ones below:

  /var/lib/mysql/ r,
  /var/lib/mysql/** rwk,

You may also need to change these lines:

  /var/run/mysqld/mysqld.pid w,
  /var/run/mysqld/mysqld.sock w,

to

  /run/mysqld/mysqld.pid w,
  /run/mysqld/mysqld.sock w,

Change these lines to reflect the new path to your database then restart MySQL.

sudo /etc/init.d/mysql restart

You may have to kill processes before you can start it again.

Add/Change Permissions

The second issue you may run into is an error about permissions:

/usr/bin/mysqladmin: connect to server at 'localhost' failed
error: 'Access denied for user 'debian-sys-maint'@'localhost' (using password: YES)'

Look in the /etc/mysql/debian.cnf for the debian-sys-maint password then login to mysql and run the command below changing <password> to the one you found in /etc/mysql/debian.cnf.

$ mysql -uroot -p

GRANT ALL PRIVILEGES ON *.* TO 'debian-sys-maint'@'localhost' IDENTIFIED BY '<password>' WITH GRANT OPTION;

At this point you may have to kill mysql one more times, but subsequent stop/restart commands should work fine.