2.10.1 Postinstallation Procedures for Unix-like Systems

2.10.1.1 Problems Running mysql_install_db
2.10.1.2 Starting and Stopping MySQL Automatically
2.10.1.3 Starting and Troubleshooting the MySQL Server

After installing MySQL on a Unix-like system, you must initialize the grant tables, start the server, and make sure that the server works satisfactorily. You may also wish to arrange for the server to be started and stopped automatically when your system starts and stops. You should also assign passwords to the accounts in the grant tables.

On a Unix-like system, the grant tables are set up by the mysql_install_db program. For some installation methods, this program is run for you automatically if an existing database cannot be found.

For other platforms and installation types, including generic binary and source installs, you will need to run mysql_install_db yourself.

The following procedure describes how to initialize the grant tables (if that has not previously been done) and start the server. It also suggests some commands that you can use to test whether the server is accessible and working properly. For information about starting and stopping the server automatically, see Section 2.10.1.2, “Starting and Stopping MySQL Automatically”.

After you complete the procedure and have the server running, you should assign passwords to the accounts created by mysql_install_db and perhaps restrict access to test databases. For instructions, see Section 2.10.2, “Securing the Initial MySQL Accounts”.

In the examples shown here, the server runs under the user ID of the mysql login account. This assumes that such an account exists. Either create the account if it does not exist, or substitute the name of a different existing login account that you plan to use for running the server. For information about creating the account, see Creating a mysql System User and Group, in Section 2.2, “Installing MySQL on Unix/Linux Using Generic Binaries”.

  1. Change location into the top-level directory of your MySQL installation, represented here by BASEDIR:

    shell> cd BASEDIR
    

    BASEDIR is the installation directory for your MySQL instance. It is likely to be something like /usr/local/mysql, /usr/local, or /usr/bin (for installation wtih MySQL Yum repository, or other means). The following steps assume that you have changed location to this directory.

    You will find several files and subdirectories in the BASEDIR directory. The most important for installation purposes are the bin and scripts subdirectories:

    • The bin directory contains client programs and the server. You should add the full path name of this directory to your PATH environment variable so that your shell finds the MySQL programs properly. See Section 2.12, “Environment Variables”.

    • The scripts directory contains the mysql_install_db script used to initialize the mysql database containing the grant tables that store the server access permissions.

  2. If necessary, ensure that the distribution contents are accessible to mysql. If you installed the distribution as mysql, no further action is required. If you installed the distribution as root, its contents will be owned by root. Change its ownership to mysql by executing the following commands as root in the installation directory. The first command changes the owner attribute of the files to the mysql user. The second changes the group attribute to the mysql group.

    shell> chown -R mysql .
    shell> chgrp -R mysql .
    
  3. If necessary, run the mysql_install_db program to set up the initial MySQL grant tables containing the privileges that determine how users are permitted to connect to the server. You will need to do this if you used a distribution type for which the installation procedure does not run the program for you.

    shell> scripts/mysql_install_db --user=mysql
    

    Typically, mysql_install_db needs to be run only the first time you install MySQL, so you can skip this step if you are upgrading an existing installation, However, mysql_install_db does not overwrite any existing privilege tables, so it should be safe to run in any circumstances.

    It might be necessary to specify other options such as --basedir or --datadir if mysql_install_db does not identify 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
    

    The mysql_install_db script creates the server's data directory with mysql as the owner. Under the data directory, it creates directories for the mysql database that holds the grant tables and the test database that you can use to test MySQL. The script also creates privilege table entries for root and anonymous-user accounts. The accounts have no passwords initially. Section 2.10.2, “Securing the Initial MySQL Accounts”, describes the initial privileges. Briefly, these privileges permit the MySQL root user to do anything, and permit anybody to create or use databases with a name of test or starting with test_. See Section 6.2, “The MySQL Access Privilege System”, for a complete listing and description of the grant tables.

    For a more secure installation, invoke mysql_install_db with the --random-passwords option. This causes it to assign a random password to the MySQL root accounts, set the password expired flag for those accounts, and remove the anonymous-user MySQL accounts. For additional details, see Section 4.4.3, “mysql_install_db — Initialize MySQL Data Directory”. (Install operations using RPMs for Unbreakable Linux Network are unaffected because they do not use mysql_install_db.)

    It is important to make sure that the database directories and files are owned by the mysql login account so that the server has read and write access to them when you run it later. To ensure this if you run mysql_install_db as root, include the --user option as shown. Otherwise, you should execute the script while logged in as mysql, in which case you can omit the --user option from the command.

    If you do not want to have the test database, you can remove it after starting the server, using the instructions in Section 2.10.2, “Securing the Initial MySQL Accounts”.

    If you have trouble with mysql_install_db at this point, see Section 2.10.1.1, “Problems Running mysql_install_db.

  4. Most of the MySQL installation can be owned by root if you like. The exception is that the data directory must be owned by mysql. To accomplish this, run the following commands as root in the installation directory:

    shell> chown -R root .
    shell> chown -R mysql data
    
  5. If the plugin directory (the directory named by the plugin_dir system variable) is writable by the server, it may be possible for a user to write executable code to a file in the directory using SELECT ... INTO DUMPFILE. This can be prevented by making plugin_dir read only to the server or by setting --secure-file-priv to a directory where SELECT writes can be made safely.

  6. If you installed MySQL using a source distribution, you may want to optionally copy one of the provided configuration files from the support-files directory into your /etc directory. There are different sample configuration files for different use cases, server types, and CPU and RAM configurations. If you want to use one of these standard files, you should copy it to /etc/my.cnf, or /etc/mysql/my.cnf and edit and check the configuration before starting your MySQL server for the first time.

    If you do not copy one of the standard configuration files, the MySQL server will be started with the default settings.

    If you want MySQL to start automatically when you boot your machine, you can copy support-files/mysql.server to the location where your system has its startup files. More information can be found in the mysql.server script itself, and in Section 2.10.1.2, “Starting and Stopping MySQL Automatically”.

  7. Start the MySQL server:

    shell> bin/mysqld_safe --user=mysql &
    

    It is important that the MySQL server be run using an unprivileged (non-root) login account. To ensure this if you run mysqld_safe as root, include the --user option as shown. Otherwise, you should execute the script while logged in as mysql, in which case you can omit the --user option from the command.

    For further instructions for running MySQL as an unprivileged user, see Section 6.1.5, “How to Run MySQL as a Normal User”.

    If the command fails immediately and prints mysqld ended, look for information in the error log (which by default is the host_name.err file in the data directory).

    If you neglected to create the grant tables by running mysql_install_db before proceeding to this step, the following message appears in the error log file when you start the server:

    mysqld: Can't find file: 'host.frm'
    

    This error also occurs if you run mysql_install_db as root without the --user option. Remove the data directory and run mysql_install_db with the --user option as described previously.

    If you have other problems starting the server, see Section 2.10.1.3, “Starting and Troubleshooting the MySQL Server”. For more information about mysqld_safe, see Section 4.3.2, “mysqld_safe — MySQL Server Startup Script”.

  8. Use mysqladmin to verify that the server is running. The following commands provide simple tests to check whether the server is up and responding to connections:

    shell> bin/mysqladmin version
    shell> bin/mysqladmin variables
    

    The output from mysqladmin version varies slightly depending on your platform and version of MySQL, but should be similar to that shown here:

    shell> bin/mysqladmin version
    mysqladmin  Ver 14.12 Distrib 5.6.22, for pc-linux-gnu on i686
    ...
    
    Server version          5.6.22
    Protocol version        10
    Connection              Localhost via UNIX socket
    UNIX socket             /var/lib/mysql/mysql.sock
    Uptime:                 14 days 5 hours 5 min 21 sec
    
    Threads: 1  Questions: 366  Slow queries: 0
    Opens: 0  Flush tables: 1  Open tables: 19
    Queries per second avg: 0.000
    

    To see what else you can do with mysqladmin, invoke it with the --help option.

  9. Verify that you can shut down the server:

    shell> bin/mysqladmin -u root shutdown
    
  10. Verify that you can start the server again. Do this by using mysqld_safe or by invoking mysqld directly. For example:

    shell> bin/mysqld_safe --user=mysql &
    

    If mysqld_safe fails, see Section 2.10.1.3, “Starting and Troubleshooting the MySQL Server”.

  11. Run some simple tests to verify that you can retrieve information from the server. The output should be similar to what is shown here:

    shell> bin/mysqlshow
    +--------------------+
    |     Databases      |
    +--------------------+
    | information_schema |
    | mysql              |
    | test               |
    +--------------------+
    
    shell> bin/mysqlshow mysql
    Database: mysql
    +---------------------------+
    |          Tables           |
    +---------------------------+
    | columns_priv              |
    | db                        |
    | event                     |
    | func                      |
    | help_category             |
    | help_keyword              |
    | help_relation             |
    | help_topic                |
    | host                      |
    | plugin                    |
    | proc                      |
    | procs_priv                |
    | servers                   |
    | tables_priv               |
    | time_zone                 |
    | time_zone_leap_second     |
    | time_zone_name            |
    | time_zone_transition      |
    | time_zone_transition_type |
    | user                      |
    +---------------------------+
    
    shell> bin/mysql -e "SELECT Host,Db,User FROM db" mysql
    +------+--------+------+
    | host | db     | user |
    +------+--------+------+
    | %    | test   |      |
    | %    | test_% |      |
    +------+--------+------+
    
  12. There is a benchmark suite in the sql-bench directory (under the MySQL installation directory) that you can use to compare how MySQL performs on different platforms. The benchmark suite is written in Perl. It requires the Perl DBI module that provides a database-independent interface to the various databases, and some other additional Perl modules:

    DBI
    DBD::mysql
    Data::Dumper
    Data::ShowTable
    

    These modules can be obtained from CPAN (http://www.cpan.org/). See also Section 2.13.1, “Installing Perl on Unix”.

    The sql-bench/Results directory contains the results from many runs against different databases and platforms. To run all tests, execute these commands:

    shell> cd sql-bench
    shell> perl run-all-tests
    

    If you do not have the sql-bench directory, you probably installed MySQL using RPM files other than the source RPM. (The source RPM includes the sql-bench benchmark directory.) In this case, you must first install the benchmark suite before you can use it. There are separate benchmark RPM files named mysql-bench-VERSION.i386.rpm that contain benchmark code and data.

    If you have a source distribution, there are also tests in its tests subdirectory that you can run. For example, to run auto_increment.tst, execute this command from the top-level directory of your source distribution:

    shell> mysql -vvf test < ./tests/auto_increment.tst
    

    The expected result of the test can be found in the ./tests/auto_increment.res file.

  13. At this point, you should have the server running. However, none of the initial MySQL accounts have a password, and the server permits permissive access to test databases. To tighten security, follow the instructions in Section 2.10.2, “Securing the Initial MySQL Accounts”.

The MySQL 5.6 installation procedure creates time zone tables in the mysql database but does not populate them. To do so, use the instructions in Section 10.6, “MySQL Server Time Zone Support”.

To make it more convenient to invoke programs installed in the bin directory under the installation directory, you can add that directory to your PATH environment variable setting. That enables you to run a program by typing only its name, not its entire path name. See Section 4.2.10, “Setting Environment Variables”.