How to Install MySQL on Ubuntu 20.04 LTS

This guide walks you through installing MySQL on Ubuntu 20.04 LTS, covering both the default repository version and the official MySQL APT repository. You’ll end with a running MySQL server, a secured root account, and a test database you can query.

What You’ll Need

• A machine running Ubuntu 20.04 LTS with an internet connection.
• sudo access (a user in the sudo group).
• Basic comfort with the terminal.

Step-by-Step

1. Update package lists
   Open a terminal and run:
   sudo apt update
   This refreshes the list of available packages from the repositories.
2. Install MySQL server
   Run:
   sudo apt install mysql-server -y
   The -y automatically confirms the installation. This installs MySQL 8.0 from Ubuntu’s default repositories.
3. Check the service status
   After installation, verify the service is running:
   sudo systemctl status mysql
   You should see active (running). If it’s not running, start it with sudo systemctl start mysql.
4. Run the security script
   MySQL ships with a security script that helps you set a root password and remove insecure defaults. Run:
   sudo mysql_secure_installation
   Follow the prompts: set a password for root (if you want), remove anonymous users, disallow root login remotely, remove the test database, and reload privileges. The script asks about VALIDATE PASSWORD COMPONENT – you can skip it or enable it, but if you enable it, choose a strong password that meets the policy.
5. Log in to MySQL
   To access the MySQL shell as root, use:
   sudo mysql
   On a fresh Ubuntu installation, root uses the auth_socket plugin by default, so you don’t need a password when using sudo. You’ll see the mysql> prompt.
6. Create a test database and user (optional but recommended)
   At the MySQL prompt, run:
   CREATE DATABASE testdb;
CREATE USER 'testuser'@'localhost' IDENTIFIED BY 'YourStrongPassword';
GRANT ALL PRIVILEGES ON testdb.* TO 'testuser'@'localhost';
FLUSH PRIVILEGES;
   Exit with EXIT;.
7. Test the new user
   Log out of the sudo session and try:
   mysql -u testuser -p
   Enter the password you set. You should get a MySQL prompt. Run SHOW DATABASES; to see testdb.
8. Enable MySQL to start on boot (usually automatic)
   If you want to be sure, run:
   sudo systemctl enable mysql
   This ensures MySQL starts automatically when the system boots.

Common Mistakes

• Forgetting to run the security script – leaving anonymous users and the test database can be a security risk.
• Assuming root uses a password – on Ubuntu, root uses auth_socket, so sudo mysql works without a password. If you try mysql -u root -p without sudo, it will fail.
• Using a weak password – even if you skip the validate component, choose a strong password for any user you create.
• Not checking the service status – if MySQL doesn’t start, you might miss an error. Always check with systemctl status.
• Editing config files without backup – if you modify /etc/mysql/mysql.conf.d/mysqld.cnf, make a backup first (sudo cp).

Tips

• Use a dedicated user for applications – don’t use root for your web app; create a user with only the privileges it needs.
• Back up your database regularly – use mysqldump to export databases: mysqldump -u user -p dbname > backup.sql.
• Monitor logs – MySQL logs are in /var/log/mysql/. Check error.log if something goes wrong.
• Consider the official MySQL repository – if you need a newer version than 8.0.25 (the default in 20.04), download the .deb from MySQL’s site and install it with dpkg. But for most users, the default is fine.
• Use MySQL Workbench or phpMyAdmin – for a GUI, install mysql-workbench or phpmyadmin for easier management.

Troubleshooting

• Can’t connect to the MySQL shell – If sudo mysql fails, try sudo service mysql start first. If you get an error about the socket, check /var/run/mysqld/ exists and is writable.
• Access denied for user ‘root’@’localhost’ – This usually means you’re not using sudo. Use sudo mysql. If you’ve already set a root password and want to switch back to socket auth, run ALTER USER 'root'@'localhost' IDENTIFIED WITH auth_socket; while logged in as root.
• MySQL won’t start – Check the error log: sudo tail -f /var/log/mysql/error.log. Common causes: disk full, permission issues on the data directory (/var/lib/mysql), or a misconfigured config file. Try sudo systemctl status mysql for more details.
• Forgot the root password – If you set a password and forgot it, you can reset it by starting MySQL in safe mode: stop the service (sudo systemctl stop mysql), start it with sudo mysqld_safe --skip-grant-tables &, then log in without password and update the root password. Be careful: this is a security risk, so do it only on a local machine.
• Port 3306 already in use – Another MySQL instance or service might be running. Check with sudo lsof -i :3306 and stop the conflicting process.

Frequently Asked Questions

Do I need to install MySQL or MariaDB?

MySQL and MariaDB are compatible alternatives. Ubuntu 20.04 offers both; this guide covers MySQL. If you prefer MariaDB, the steps are similar (sudo apt install mariadb-server).

How do I change the root password?

Log in with sudo mysql, then run: ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'NewPassword'; Then FLUSH PRIVILEGES;. After that, you’ll need to use mysql -u root -p with the new password.

Can I install MySQL from the official MySQL site instead?

Yes. Download the MySQL APT repository .deb from dev.mysql.com, install it with sudo dpkg -i mysql-apt-config_*.deb, then run sudo apt update and sudo apt install mysql-server. This gives you the latest version, but you must manage the repository yourself.

How do I allow remote connections to MySQL?

Edit /etc/mysql/mysql.conf.d/mysqld.cnf, change bind-address to 0.0.0.0, restart MySQL, and create a user with a host of % or a specific IP. Also ensure your firewall allows port 3306. This is not recommended for production without proper security.

Why does mysql_secure_installation ask about the validate password plugin?

That plugin enforces password strength. You can skip it, but if you enable it, you must choose a password that meets the length and complexity requirements. You can later disable it if it causes issues, but it’s a good security practice.

How do I uninstall MySQL completely?

Run sudo apt purge mysql-server mysql-client mysql-common, then sudo apt autoremove. Also remove the data directory with sudo rm -rf /var/lib/mysql if you want to erase all databases. Be careful: this is irreversible.

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