mysqld_safe - Man Page

mysqld_safe options

mysqld_safe is the recommended way to start a mysqld server on Unix​. 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 is given later in this section​.

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​.

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​.

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 current installations​.

mysqld_safe supports the options in the following list​. It also reads option files and supports the options for processing them.

• --help

  Display a help message and exit​.

• --basedir=path

  The path to the MariaDB 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​.

• --crash-script=file

  Script to call in the event of mysqld crashing​.

• --datadir=path

  The path to the data directory​.

• --defaults-extra-file=path

  The name of an option file to be read in addition to the usual option files​. This must be the first option on the command line if it is used​. If the file does not exist or is otherwise inaccessible, the server will exit with an error​.

• --defaults-file=file_name

  The name of an option file to be read instead of the usual option files​. This must be the first option on the command line if it is used​.

• --flush-caches

  Flush and purge buffers/caches before starting the server​.

• --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​.

• --malloc-lib=lib

  Preload shared library lib if available​.

• --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 MariaDB 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-auto-restart, --nowatch, --no-watch

  Exit after starting mysqld​.

• --no-defaults

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

• --numa-interleave

  Run mysqld with its memory interleaved on all NUMA nodes​.

• --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​.

• --plugin-dir=dir_name

  Directory for client-side plugins​.

• --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​.

• --syslog, --skip-syslog

  --syslog causes error messages to be sent to syslog on systems that support the logger program​. --skip-syslog suppresses the use of syslog; messages are written to an error log file​.

• --syslog-tag=tag

  For logging to syslog, messages from mysqld_safe and mysqld are written with a tag of mysqld_safe and mysqld, respectively​. To specify a suffix for the tag, use --syslog-tag=tag, which modifies the tags to be mysqld_safe-tag and mysqld-tag​.

• --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 MariaDB 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 MariaDB, even though these types of distributions typically install the server in slightly different locations​. 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 MariaDB 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 MariaDB 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 MariaDB anywhere, as long as you run mysqld_safe from the MariaDB installation directory:

shell> cd mysql_installation_directory
shell> bin/mysqld_safe &

If mysqld_safe fails, even when invoked from the MariaDB 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​.

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​.
• --skip-syslog: Do not write error messages to syslog​. Messages are written to the default error log file (host_name​.err in the data directory), or to a named file if the --log-error option is given​.
• --log-error=file_name: Write error messages to the named error file​.

If none of these options is given, the default is --skip-syslog​.

If --syslog and --log-error are both given, a warning is issued and --log-error takes precedence​.

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​.

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 MariaDB 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 MariaDB 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​.

Copyright 2007-2008 MySQL AB, 2008-2010 Sun Microsystems, Inc., 2010-2020 MariaDB Foundation

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 02110-1335 USA or see http://www.gnu.org/licenses/.

For more information, please refer to the MariaDB Documentation, available online at https://mariadb.com/docs/

MariaDB Foundation (http://www.mariadb.org/).