4.4.3. mysql_install_db — Initialize MySQL Data Directory

mysql_install_db initializes the MySQL data directory and creates the system tables that it contains, if they do not exist. It also initializes the system tablespace and related data structures needed to manage InnoDB tables. mysql_install_db is a Perl script and can be used on any system with Perl installed.

On Unix platforms, mysql_install_db creates a default option file named my.cnf in the base installation directory. This file is created from a template included in the distribution package named my-default.cnf. You can find the template in or under the base installation directory. When started using mysqld_safe, the server uses my.cnf file by default. If my.cnf already exists, mysql_install_db assumes it to be in use and writes a new file named my-new.cnf instead.

With one exception, the settings in the default option file are commented and have no effect. The exception is that the file changes the sql_mode system variable from its default of NO_ENGINE_SUBSTITUTION to also include STRICT_TRANS_TABLES. This setting produces a server configuration that results in errors rather than warnings for bad data in operations that modify transactional tables. See Section 5.1.7, "Server SQL Modes".

To invoke mysql_install_db, use the following syntax:

shell> mysql_install_db [options]

Because the MySQL server, mysqld, needs to access the data directory when it runs later, you should either run mysql_install_db from the same system account that will be used for running mysqld or run it as root and use the --user option to indicate the user name that mysqld will run as. It might be necessary to specify other options such as --basedir or --datadir if mysql_install_db does not use the correct locations for the installation directory or data directory. For example:

shell> scripts/mysql_install_db --user=mysql \         --basedir=/opt/mysql/mysql \         --datadir=/opt/mysql/mysql/data

mysql_install_db needs to invoke mysqld with the --bootstrap and --skip-grant-tables options.

Note

If you have set a custom TMPDIR environment variable when performing the installation, and the specified directory is not accessible, mysql_install_db may fail. If so, unset TMPDIR or set TMPDIR to point to the system temporary directory (usually /tmp).

After mysql_install_db sets up the InnoDB system tablespace, changes to some of tablespace characteristics require setting up a whole new instance. This includes the file name of the first file in the system tablespace and the number of undo logs. If you do not want to use the default values, make sure that the settings for the innodb_data_file_path and innodb_log_file_size configuration options are in place in the MySQL configuration file before running mysql_install_db.

mysql_install_db supports the following options, which can be specified on the command line or in the [mysql_install_db] group of an option file. (Options that are common to mysqld can also be specified in the [mysqld] group.) Other options are passed to mysqld. For information about option files, see Section 4.2.3.3, "Using Option Files". mysql_install_db also supports the options for processing option files described at Section 4.2.3.4, "Command-Line Options that Affect Option-File Handling".

--basedir=path

The path to the MySQL installation directory.
--datadir=path, --ldata=path

The path to the MySQL data directory. Only the last component of the path name is created if it does not exist; the parent directory must already exist or an error occurs.
--force

Cause mysql_install_db to run even if DNS does not work. Grant table entries that normally use host names will use IP addresses.
--random-passwords

On Unix platforms, this option provides for more secure MySQL installation. Invoking mysql_install_db with --random-passwords causes it to perform the following actions in addition to its normal operation:
- Create a random password, assign it to the initial MySQL root accounts, and set the "password expired" flag for those accounts.
- Write the initial password file to the .mysql_secret file in the directory named by the HOME environment variable. Depending on operating system, using a command such as sudo may cause the value of HOME to refer to the home directory of the root system user.
  
  If .mysql_secret already exists, the new password information is appended to it. Each password entry includes a timestamp so that in the event of multiple install operations it is possible to determine the password associated with each one.
  
  .mysql_secret is created with mode 600 to be accessible only to the system user for whom it is created.
- Remove the anonymous-user MySQL accounts.
As a result of these actions, it is necessary after installation to start the server, connect as root using the password written to the .mysql_secret file, and to assign a new root password. Until this is done, root cannot do anything else. This must be done for each root account you intend to use. To change the password, you can use the SET PASSWORD statement (for example, with the mysql client). You can also use mysqladmin or mysql_secure_installation.

New install operations (not upgrades) using RPM packages and Solaris PKG packages invoke mysql_install_db with the --random-passwords option. (Install operations using RPMs for Unbreakable Linux Network are unaffected because they do not use mysql_install_db.)

For install operations using a binary .tar.gz distribution or a source distribution, you can invoke mysql_install_db with the --random-passwords option manually to make your MySQL installation more secure. This is recommended, particularly for sites with sensitive data.
--rpm

For internal use. This option is used during the MySQL installation process for install operations performed using RPM packages.
--skip-name-resolve

Use IP addresses rather than host names when creating grant table entries. This option can be useful if your DNS does not work.
--srcdir=path

For internal use. This option specifies the directory under which mysql_install_db looks for support files such as the error message file and the file for populating the help tables.
--user=user_name

The system (login) user name to use for running mysqld. Files and directories created by mysqld will be owned by this user. You must be root to use this option. By default, mysqld runs using your current login name and files and directories that it creates will be owned by you.
--verbose

Verbose mode. Print more information about what the program does.
--windows

For internal use. This option is used for creating Windows distributions.