Modify the MySQL data directory in Ubuntu/Linux

OS: Ubuntu  20.04 64bit

MySQL version: MySQL 8

1. Copy the default directory

First of all, please be sure to close the MySQL service:

sudo service mysql stop

Create a new directory in your desired location to use as the MySQL data directory:

mkdir /your_data_folder

Then, go to the directory /var/lib/mysql:

cd /var/lib/mysql

There are many contents under this directory:

Copy all the contents of this directory into the newly created directory you just created:

sudo cp -R /var/lib/mysql/* /your_data_folder

 Second, modify the MySQL configuration file

Enter the directory /etc/mysql/mysql.conf.d and find the file mysqld.cnf:

 Open this file:

sudo vim mysqld.cnf

In the file, find the "datadir" line, and change the path to the newly created directory:

3. Modify apparmor

Enter the following directory: /etc/apparmor.d, find the file named usr.sbin.mysqld:

Open the file for editing:

sudo vim usr.sbin.mysqld

Locate the Allow data dir access configuration area in the file:

Change the directory path to the directory path you just created, pay attention to keep the last / r and /** rwk

4. Start MySQL

If everything is modified correctly, MySQL can be started normally: