mysqld_safe - MySQL server startup script at Linux.org

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MYSQLD_SAFE(1) MySQL Database System MYSQLD_SAFE(1)

NAME
mysqld_safe - MySQL server startup script

SYNOPSIS
mysqld_safe options

DESCRIPTION
mysqld_safe is the recommended way to start a mysqld server on Unix and NetWare. mysqld_safe adds some safety
features such as restarting the server when an error occurs and logging runtime information to an error log
file. Descriptions of error logging and NetWare-specific behaviors are given later in this section.

Note
In MySQL 5.1.20 (only), the default error logging behavior with mysqld_safe is to write errors to syslog
on systems that support the logger program. This differs from the default behavior of writing an error log
file for other versions.

In 5.1.20, logging to syslog may fail to operate correctly in some cases; if so, use --skip-syslog to use
the default log file or --log-error=file_name to specify a log file name explicitly.

mysqld_safe tries to start an executable named mysqld. To override the default behavior and specify explicitly
the name of the server you want to run, specify a --mysqld or --mysqld-version option to mysqld_safe. You can
also use --ledir to indicate the directory where mysqld_safe should look for the server.

Many of the options to mysqld_safe are the same as the options to mysqld. See Section 5.1.2, “Server Command
Options”.

Options unknown to mysqld_safe are passed to mysqld if they are specified on the command line, but ignored if
they are specified in the [mysqld_safe] or [mariadb_safe] groups of an option file. See Section 4.2.3.3,
“Using Option Files”.

mysqld_safe reads all options from the [mysqld], [server], [mysqld_safe], and [mariadb_safe] sections in
option files. For example, if you specify a [mysqld] section like this, mysqld_safe will find and use the
--log-error option:

[mysqld]
log-error=error.log

For backward compatibility, mysqld_safe also reads [safe_mysqld] sections, although you should rename such
sections to [mysqld_safe] in MySQL 5.1 installations.

mysqld_safe supports the options in the following list. It also reads option files and supports the options
for processing them described at Section 4.2.3.3.1, “Command-Line Options that Affect Option-File Handling”.

· --help

Display a help message and exit.

· --basedir=path

The path to the MySQL installation directory.

· --core-file-size=size

The size of the core file that mysqld should be able to create. The option value is passed to ulimit -c.

· --datadir=path

the command line if it is used.

· --ledir=path

If mysqld_safe cannot find the server, use this option to indicate the path name to the directory where
the server is located.

· --log-error=file_name

Write the error log to the given file. See Section 5.2.2, “The Error Log”.

· --mysqld=prog_name

The name of the server program (in the ledir directory) that you want to start. This option is needed if
you use the MySQL binary distribution but have the data directory outside of the binary distribution. If
mysqld_safe cannot find the server, use the --ledir option to indicate the path name to the directory
where the server is located.

· --mysqld-version=suffix

This option is similar to the --mysqld option, but you specify only the suffix for the server program
name. The basename is assumed to be mysqld. For example, if you use --mysqld-version=debug, mysqld_safe
starts the mysqld-debug program in the ledir directory. If the argument to --mysqld-version is empty,
mysqld_safe uses mysqld in the ledir directory.

· --nice=priority

Use the nice program to set the server´s scheduling priority to the given value.

· --no-defaults

Do not read any option files. This must be the first option on the command line if it is used.

· --open-files-limit=count

The number of files that mysqld should be able to open. The option value is passed to ulimit -n. Note that
you need to start mysqld_safe as root for this to work properly!

· --pid-file=file_name

The path name of the process ID file.

· --port=port_num

The port number that the server should use when listening for TCP/IP connections. The port number must be
1024 or higher unless the server is started by the root system user.

· --skip-kill-mysqld

Do not try to kill stray mysqld processes at startup. This option works only on Linux.

· --socket=path

The Unix socket file that the server should use when listening for local connections.

· --timezone=timezone

Set the TZ time zone environment variable to the given option value. Consult your operating system
documentation for legal time zone specification formats.

· --user={user_name|user_id}

Run the mysqld server as the user having the name user_name or the numeric user ID user_id. (“User” in
this context refers to a system login account, not a MySQL user listed in the grant tables.)

If you execute mysqld_safe with the --defaults-file or --defaults-extra-file option to name an option file,
the option must be the first one given on the command line or the option file will not be used. For example,
this command will not use the named option file:

mysql> mysqld_safe --port=port_num --defaults-file=file_name

Instead, use the following command:

mysql> mysqld_safe --defaults-file=file_name --port=port_num

The mysqld_safe script is written so that it normally can start a server that was installed from either a
source or a binary distribution of MySQL, even though these types of distributions typically install the
server in slightly different locations. (See Section 2.1.5, “Installation Layouts”.) mysqld_safe expects one
of the following conditions to be true:

· The server and databases can be found relative to the working directory (the directory from which
mysqld_safe is invoked). For binary distributions, mysqld_safe looks under its working directory for bin
and data directories. For source distributions, it looks for libexec and var directories. This condition
should be met if you execute mysqld_safe from your MySQL installation directory (for example,
/usr/local/mysql for a binary distribution).

· If the server and databases cannot be found relative to the working directory, mysqld_safe attempts to
locate them by absolute path names. Typical locations are /usr/local/libexec and /usr/local/var. The
actual locations are determined from the values configured into the distribution at the time it was built.
They should be correct if MySQL is installed in the location specified at configuration time.

Because mysqld_safe tries to find the server and databases relative to its own working directory, you can
install a binary distribution of MySQL anywhere, as long as you run mysqld_safe from the MySQL installation
directory:

shell> cd mysql_installation_directory
shell> bin/mysqld_safe &

If mysqld_safe fails, even when invoked from the MySQL installation directory, you can specify the --ledir and
--datadir options to indicate the directories in which the server and databases are located on your system.

When you use mysqld_safe to start mysqld, mysqld_safe arranges for error (and notice) messages from itself and
from mysqld to go to the same destination.

As of MySQL 5.1.20, there are several mysqld_safe options for controlling the destination of these messages:

· --syslog: Write error messages to syslog on systems that support the logger program.

When mysqld_safe writes a message, notices go to the logging destination (syslog or the error log file) and
stdout. Errors go to the logging destination and stderr.

Before MySQL 5.1.20, error logging is controlled only with the --log-error option. If it is given, messages go
to the named error file. Otherwise, messages go to the default error file.

Normally, you should not edit the mysqld_safe script. Instead, configure mysqld_safe by using command-line
options or options in the [mysqld_safe] section of a my.cnf option file. In rare cases, it might be necessary
to edit mysqld_safe to get it to start the server properly. However, if you do this, your modified version of
mysqld_safe might be overwritten if you upgrade MySQL in the future, so you should make a copy of your edited
version that you can reinstall.

On NetWare, mysqld_safe is a NetWare Loadable Module (NLM) that is ported from the original Unix shell script.
It starts the server as follows:

1. Runs a number of system and option checks.

2. Runs a check on MyISAM tables.

3. Provides a screen presence for the MySQL server.

4. Starts mysqld, monitors it, and restarts it if it terminates in error.

5. Sends error messages from mysqld to the host_name.err file in the data directory.

6. Sends mysqld_safe screen output to the host_name.safe file in the data directory.

This documentation is free software; you can redistribute it and/or modify it only under the terms of the GNU
General Public License as published by the Free Software Foundation; version 2 of the License.

This documentation is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
License for more details.

You should have received a copy of the GNU General Public License along with the program; if not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see
http://www.gnu.org/licenses/.

SEE ALSO
For more information, please refer to the MySQL Reference Manual, which may already be installed locally and
which is also available online at http://dev.mysql.com/doc/.

AUTHOR
Sun Microsystems, Inc. (http://www.mysql.com/).

MySQL 5.1 04/06/2010 MYSQLD_SAFE(1)