MariaDB¶

What Is It?¶

MariaDB is an open-source relational database management system, a fork of MySQL. It is used as the backend database for applications like WordPress.

Installation¶

dnf install mariadb-server

Key Files and Directories¶

Path	Purpose
/etc/my.cnf	Main configuration
/etc/my.cnf.d/	Additional configuration
/var/lib/mysql/	Database files

Default Ports¶

Port	Protocol	Purpose
3306	TCP	MariaDB/MySQL client connections

Configuration¶

MariaDB uses a hierarchical configuration system:

/etc/my.cnf — main configuration file
/etc/my.cnf.d/ — additional configuration files (loaded automatically)
/var/lib/mysql/ — database data files

Minimal Working Configuration¶

Installation and initial setup:

# Install
sudo dnf install mariadb-server

# Start and enable
sudo systemctl start mariadb
sudo systemctl enable mariadb

# Secure the installation
sudo mysql_secure_installation

The mysql_secure_installation script walks through:

Setting a root password
Removing anonymous users
Disabling remote root login
Removing the test database
Reloading privilege tables

Creating a database and user (for WordPress or other applications):

-- Connect to MariaDB
mysql -u root -p

-- Create a database
CREATE DATABASE wordpress;

-- Create a user with a password
CREATE USER 'admin'@'localhost' IDENTIFIED BY 'secure_password';

-- Grant privileges on the database
GRANT ALL ON wordpress.* TO 'admin'@'localhost';

-- Apply changes
FLUSH PRIVILEGES;

-- Exit
exit;

Important Directives¶

bind-address: Which IP address MariaDB listens on. Default 127.0.0.1 (localhost only). Set to 0.0.0.0 to accept remote connections (use with caution).
port: TCP port for connections. Default is 3306.
datadir: Location of database files. Default /var/lib/mysql/.
max_connections: Maximum number of simultaneous client connections.
character-set-server: Default character set. Use utf8mb4 for full Unicode support.
skip-networking: Disable TCP/IP connections entirely (only UNIX socket). Useful when the application and database are on the same host.

Common Commands¶

# Connect to MariaDB as root
mysql -u root -p

# Connect to a specific database
mysql -u admin -p wordpress

# Show databases
SHOW DATABASES;

# Show tables in current database
USE wordpress;
SHOW TABLES;

# Show users and their hosts
SELECT User, Host FROM mysql.user;

# Show grants for a user
SHOW GRANTS FOR 'admin'@'localhost';

# Backup a database
mysqldump -u root -p wordpress > wordpress_backup.sql

# Restore a database
mysql -u root -p wordpress < wordpress_backup.sql

# Check service status
systemctl status mariadb

Logging and Debugging¶

Error log: /var/log/mariadb/mariadb.log (or check log_error setting)
General query log: Enable with general_log = 1 in config (logs all queries — use only for debugging, very verbose)
Slow query log: Enable with slow_query_log = 1 to find poorly performing queries
systemd journal: journalctl -u mariadb
Connection test: mysql -u root -p -e "SELECT 1" — quick connectivity check

Troubleshooting checklist:

systemctl status mariadb — is the service running?
journalctl -u mariadb — any startup errors?
mysql -u root -p — can you connect?
Check /var/lib/mysql/ permissions — must be owned by mysql:mysql
ss -tulpn | grep 3306 — is MariaDB listening?

Security Considerations¶

Run mysql_secure_installation: Always run this after initial installation to remove defaults that are insecure for production.
Strong passwords: Never use simple passwords like pass for database users in production. Generate random passwords with openssl rand -base64 16.
Restrict access: Use 'user'@'localhost' rather than 'user'@'%' unless remote access is genuinely needed. This limits connections to the local machine.
Separate users per application: Each application should have its own database user with grants only on its own database.
Backup regularly: Use mysqldump for logical backups. Test restoration periodically.
Do not expose port 3306: Keep MariaDB listening on localhost only unless remote access is required. If needed, restrict with firewall rules.
File permissions: Database files in /var/lib/mysql/ should be owned by mysql:mysql and not world-readable.