mariadb-install-db

Initialize a database

$ sudo mariadb-install-db --user [user] --basedir [/usr] --datadir [/var/lib/mysql]

$ mariadb-install-db --help

mariadb-install-db [options]

--auth-root-authentication-method=[legacy|socket]
    Select authentication method for root. With 'legacy', the root user will authenticate with a password. With 'socket', authentication will be performed using the unix socket.

--basedir=path
    The base directory where MariaDB is installed.

--datadir=path
    The data directory where MariaDB databases are stored.

--db-bootstrap
    Bootstrap a new cluster, to be the first server of the cluster.

--defaults-file=file
    Read options from the given file only.

--force
    Force execution even if the data directory already exists. Use with caution!

--help
    Display help message and exit.

--ldata=path
    Synonym for --datadir. Deprecated.

--log-error=file
    File to write error messages.

--no-defaults
    Don't read default options from any option file.

--no-dd-upgrade
    Do not perform a data dictionary upgrade if it is needed.

--no-se-range-optimizer
    Disable the storage engine range optimizer, mainly for debugging.

--plugin-dir=path
    The directory where MariaDB plugins are located.

--service=name
    Create a systemd service file to start the server. This is automatically executed when installing from a package management system.

--skip-auth-table-grant
    Skip creating the auth tables. This is useful only for special cases, when creating user tables will be done otherwise.

--skip-create-tables
    Skip creation of the MariaDB tables.
Implies --skip-auth-table-grant.

--socket=path
    The socket file to use for local connections.

--ssl
    Create SSL certificates.

--ssl-ca=file
    The CA file to use for SSL certificates.

--ssl-cert=file
    The certificate file to use for SSL certificates.

--ssl-key=file
    The key file to use for SSL certificates.

--sysconfdir=path
    The directory where MariaDB configuration files are located.

--tmpdir=path
    The temporary directory to use.

--user=user_name
    The user account that the MariaDB server will run as.

--verbose
    More verbose output.

--wsrep-new-cluster
    Bootstrap a new Galera cluster, to be the first server of the cluster.

The `mariadb-install-db` command initializes the MariaDB data directory. This command is crucial for setting up a new MariaDB installation or when you need to re-initialize your data directory. It performs several important tasks including: creating the system tables (mysql, performance_schema, and information_schema), setting up the initial MariaDB users (including root), and generating the SSL certificates for secure connections.

Before MariaDB 10.4.3, `mariadb-install-db` was a Perl script. From MariaDB 10.4.3 onwards, it's a binary program which significantly improves performance and security. The script approach had security vulnerabilities that the binary resolves. Because `mariadb-install-db` directly modifies the file system, it's vital to run this command with appropriate user privileges, usually as the user under which the MariaDB server will run (typically `mysql`). Failing to initialize the database can cause MariaDB to fail to start, or behave unpredictably. This tool provides a secure and performant way to create and setup the data directory and its essential privileges.

Running `mariadb-install-db` with the `--force` option can potentially overwrite existing data.

Always backup your data before attempting to re-initialize your MariaDB data directory.

Ensure the user specified with `--user` has the necessary permissions to create and modify files in the data directory.

It's crucial that `mariadb-install-db` is executed with the correct user permissions, ideally the same user that will run the MariaDB server daemon. Otherwise, file ownership issues can prevent the server from starting correctly.

When upgrading MariaDB, it might be necessary to upgrade the data dictionary. By default, `mariadb-install-db` will attempt to do so. If you wish to prevent this, you can use the `--no-dd-upgrade` option. Usually is a sign that you may need to run `mysql_upgrade` command.

Prior to MariaDB 10.4.3, `mariadb-install-db` was implemented as a Perl script. This script had some performance and security limitations. From MariaDB 10.4.3 onwards, it's been re-written as a binary program using C++, significantly improving performance and security. This change addresses the vulnerabilities in the script version and provides a more robust solution for initializing the database.

mariadbd(1), mysql(1), mysqladmin(1)