MYSQLD\_SAFE(1) MySQL Database System MYSQLD\_SAFE(1)

# [NAME](#NAME)

mysqld\_safe - MySQL server startup script

# [SYNOPSIS](#SYNOPSIS)

**mysqld\_safe options**

# [DESCRIPTION](#DESCRIPTION)

**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. A description of error logging is given later in this section.

**Note**

For some Linux platforms, MySQL installation from RPM or Debian packages includes systemd support for managing MySQL server startup and shutdown. On these platforms, **mysqld\_safe** is not installed because it is unnecessary. For more information, see Section 2.5.9, “Managing MySQL Server with systemd”.

One implication of the non-use of **mysqld\_safe** on platforms that use systemd for server management is that use of \[mysqld\_safe] or \[safe\_mysqld] sections in option files is not supported and might lead to unexpected behavior.

**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 7.1.7, “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] group of an option file. See Section 6.2.2.2, “Using Option Files”.

**mysqld\_safe** reads all options from the \[mysqld], \[server], and \[mysqld\_safe] sections in option files. For example, if you specify a \[mysqld] section like this, **mysqld\_safe** finds and uses the **--log-error** option:

```
[mysqld]
log-error=error.log
```

For backward compatibility, **mysqld\_safe** also reads \[safe\_mysqld] sections, but to be current you should rename such sections to \[mysqld\_safe].

**mysqld\_safe** accepts options on the command line and in option files, as described in the following table. For information about option files used by MySQL programs, see Section 6.2.2.2, “Using Option Files”.

•**--help**

**Command-Line Format** --help

Display a help message and exit.

•**--basedir=dir\_name**

**Command-Line Format** --basedir=dir\_name **Type** Directory name

The path to the MySQL installation directory.

•**--core-file-size=size**

**Command-Line Format** --core-file-size=size **Type** String

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

**Note**  
The innodb\_buffer\_pool\_in\_core\_file variable can be used to reduce the size of core files on operating systems that support it. For more information, see Section 17.8.3.7, “Excluding Buffer Pool Pages from Core Files”.

•**--datadir=dir\_name**

**Command-Line Format** --datadir=dir\_name **Type** Directory name

The path to the data directory.

•**--defaults-extra-file=file\_name**

**Command-Line Format** --defaults-extra-file=file\_name **Type** File name

Read this option file in addition to the usual option files. If the file does not exist or is otherwise inaccessible, the server exits with an error. If *file\_name* is not an absolute path name, it is interpreted relative to the current directory. This must be the first option on the command line if it is used.

For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.

•**--defaults-file=file\_name**

**Command-Line Format** --defaults-file=file\_name **Type** File name

Use only the given option file. If the file does not exist or is otherwise inaccessible, the server exits with an error. If *file\_name* is not an absolute path name, it is interpreted relative to the current directory. This must be the first option on the command line if it is used.

For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.

•**--ledir=dir\_name**

**Command-Line Format** --ledir=dir\_name **Type** Directory name

If **mysqld\_safe** cannot find the server, use this option to indicate the path name to the directory where the server is located.

This option is accepted only on the command line, not in option files. On platforms that use systemd, the value can be specified in the value of MYSQLD\_OPTS. See Section 2.5.9, “Managing MySQL Server with systemd”.

•**--log-error=file\_name**

**Command-Line Format** --log-error=file\_name **Type** File name

Write the error log to the given file. See Section 7.4.2, “The Error Log”.

•**--mysqld-safe-log-timestamps**

**Command-Line Format** --mysqld-safe-log-timestamps=type **Type** Enumeration **Default Value** utc **Valid Values** system hyphen legacy

This option controls the format for timestamps in log output produced by **mysqld\_safe**. The following list describes the permitted values. For any other value, **mysqld\_safe** logs a warning and uses UTC format.

•UTC, utc

ISO 8601 UTC format (same as **--log\_timestamps=UTC** for the server). This is the default.

•SYSTEM, system

ISO 8601 local time format (same as **--log\_timestamps=SYSTEM** for the server).

•HYPHEN, hyphen

*YY-MM-DD h:mm:ss* format, as in **mysqld\_safe** for MySQL 5.6.

•LEGACY, legacy

*YYMMDD hh:mm:ss* format, as in **mysqld\_safe** prior to MySQL 5.6.

•**--malloc-lib=\[lib\_name]**

**Command-Line Format** --malloc-lib=\[lib-name] **Type** String

The name of the library to use for memory allocation instead of the system malloc() library. The option value must be one of the directories /usr/lib, /usr/lib64, /usr/lib/i386-linux-gnu, or /usr/lib/x86\_64-linux-gnu.

The **--malloc-lib** option works by modifying the LD\_PRELOAD environment value to affect dynamic linking to enable the loader to find the memory-allocation library when **mysqld** runs:

•If the option is not given, or is given without a value (**--malloc-lib=**), LD\_PRELOAD is not modified and no attempt is made to use tcmalloc.

•Prior to MySQL 8.0.21, if the option is given as **--malloc-lib=tcmalloc**, **mysqld\_safe** looks for a tcmalloc library in /usr/lib. If tmalloc is found, its path name is added to the beginning of the LD\_PRELOAD value for **mysqld**. If tcmalloc is not found, **mysqld\_safe** aborts with an error.

As of MySQL 8.0.21, tcmalloc is not a permitted value for the **--malloc-lib** option.

•If the option is given as **--malloc-lib=/path/to/some/library**, that full path is added to the beginning of the LD\_PRELOAD value. If the full path points to a nonexistent or unreadable file, **mysqld\_safe** aborts with an error.

•For cases where **mysqld\_safe** adds a path name to LD\_PRELOAD, it adds the path to the beginning of any existing value the variable already has.

**Note**  
On systems that manage the server using systemd, **mysqld\_safe** is not available. Instead, specify the allocation library by setting LD\_PRELOAD in /etc/sysconfig/mysql.

Linux users can use the libtcmalloc\_minimal.so library on any platform for which a tcmalloc package is installed in /usr/lib by adding these lines to the my.cnf file:

```
[mysqld_safe]
malloc-lib=tcmalloc
```

To use a specific tcmalloc library, specify its full path name. Example:

```
[mysqld_safe]
malloc-lib=/opt/lib/libtcmalloc_minimal.so
```

•**--mysqld=prog\_name**

**Command-Line Format** --mysqld=file\_name **Type** File 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.

This option is accepted only on the command line, not in option files. On platforms that use systemd, the value can be specified in the value of MYSQLD\_OPTS. See Section 2.5.9, “Managing MySQL Server with systemd”.

•**--mysqld-version=suffix**

**Command-Line Format** --mysqld-version=suffix **Type** String

This option is similar to the **--mysqld** option, but you specify only the suffix for the server program name. The base name 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.

This option is accepted only on the command line, not in option files. On platforms that use systemd, the value can be specified in the value of MYSQLD\_OPTS. See Section 2.5.9, “Managing MySQL Server with systemd”.

•**--nice=priority**

**Command-Line Format** --nice=priority **Type** Numeric

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

•**--no-defaults**

**Command-Line Format** --no-defaults **Type** String

Do not read any option files. If program startup fails due to reading unknown options from an option file, **--no-defaults** can be used to prevent them from being read. This must be the first option on the command line if it is used.

For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.

•**--open-files-limit=count**

**Command-Line Format** --open-files-limit=count **Type** String

The number of files that **mysqld** should be able to open. The option value is passed to **ulimit -n**.

**Note**  
You must start **mysqld\_safe** as root for this to function properly.

•**--pid-file=file\_name**

**Command-Line Format** --pid-file=file\_name **Type** File name

The path name that **mysqld** should use for its process ID file.

•**--plugin-dir=dir\_name**

**Command-Line Format** --plugin-dir=dir\_name **Type** Directory name

The path name of the plugin directory.

•**--port=port\_num**

**Command-Line Format** --port=number **Type** Numeric

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 operating system user.

•**--skip-kill-mysqld**

**Command-Line Format** --skip-kill-mysqld

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

•**--socket=path**

**Command-Line Format** --socket=file\_name **Type** File name

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

•**--syslog**, **--skip-syslog**

**Command-Line Format** --syslog **Deprecated** Yes

**Command-Line Format** --skip-syslog **Deprecated** Yes

**--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.

When syslog is used for error logging, the daemon.err facility/severity is used for all log messages.

Using these options to control **mysqld** logging is deprecated. To write error log output to the system log, use the instructions at Section 7.4.2.8, “Error Logging to the System Log”. To control the facility, use the server log\_syslog\_facility system variable.

•**--syslog-tag=tag**

**Command-Line Format** --syslog-tag=tag **Deprecated** Yes

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

Using this option to control **mysqld** logging is deprecated. Use the server log\_syslog\_tag system variable instead. See Section 7.4.2.8, “Error Logging to the System Log”.

•**--timezone=timezone**

**Command-Line Format** --timezone=timezone **Type** String

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}**

**Command-Line Format** --user={user\_name|user\_id} **Type** String **Type** Numeric

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 is not used. For example, this command does 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:

```
cd mysql_installation_directory
bin/mysqld_safe &
```

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

**mysqld\_safe** tries to use the **sleep** and **date** system utilities to determine how many times per second it has attempted to start. If these utilities are present and the attempted starts per second is greater than 5, **mysqld\_safe** waits 1 full second before starting again. This is intended to prevent excessive CPU usage in the event of repeated failures. (Bug #11761530, Bug #54035)

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:

•**--log-error=file\_name**: Write error messages to the named error file.

•**--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.

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

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.

**Note**

Controlling **mysqld** logging from **mysqld\_safe** is deprecated. Use the server's native syslog support instead. For more information, see Section 7.4.2.8, “Error Logging to the System Log”.

# [COPYRIGHT](#COPYRIGHT)

Copyright © 1997, 2026, Oracle and/or its affiliates.

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](#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](#AUTHOR)

Oracle Corporation (http://dev.mysql.com/).

03/23/2026 MySQL 8.0

---

Document: mysqld_safe(1) from mysql-8.0 8.0.46-r9 (Chainguard OS)
Source: https://github.com/mysql/mysql-server