SQL database is commonly used by the OpenStack services for storing the information. But other databases are also supported by OpenStack, such as PostgreSQL. The database runs on the controller node.  Below are commandsf or installing and configuring and installing components for database.  a. Install the packages.  # yum install mariadb mariadb-server python2-PyMySQL   b. Create and edit the file /etc/my.cnf.d/openstack.cnf file, and add the following [mysql] section.  [mysqld]
bind-address = 10.0.0.11
default-storage-engine = innodb
innodb_file_per_table
max_connections = 4096
collation-server = utf8_general_ci
character-set-server = utf8  c. Start the database service and make sure that the database will also start when the system boots. Below is the command.  # systemctl enable mariadb.service
# systemctl start mariadb.service  d. Run the mysql_secure_installation script for securing the database service.   # mysql_secure_installation