mariadbd-safe

The mariadbd-safe startup script is in MariaDB distributions on Linux and Unix. It is a wrapper that starts mariadbd with some extra safety features. For example, if mariadbd-safe notices that mariadbd has crashed, then mariadbd-safe will automatically restart mariadbd.

mariadbd-safe is the recommended way to start mariadbd on Linux and Unix distributions that do not support systemd. Additionally, the mysql.server init script used by sysVinit starts mariadbd with mariadbd-safe by default.

Prior to MariaDB 10.5, the client used to be called mysqld_safe, and can still be accessed under this name, via a symlink in Linux, or an alternate binary in Windows.

Using mariadbd-safe

The command to use mariadbd-safe and the general syntax is:

mariadbd-safe [ --no-defaults | --defaults-file | --defaults-extra-file | --defaults-group-suffix | --print-defaults ] <options> <mariadbd_options>

Options

Many of the options supported by mariadbd-safe are identical to options supported by mariadbd. If an unknown option is provided to mariadbd-safe on the command-line, then it is passed to mariadbd.

mariadbd-safe supports the following options:

Option Files

In addition to reading options from the command-line, mariadbd-safe can also read options from option files. If an unknown option is provided to mariadbd-safe in an option file, then it is ignored.

The following options relate to how MariaDB command-line tools handles option files. They must be given as the first argument on the command-line:

Option Groups

mariadbd-safe reads options from the following option groups from option files:

The [safe_mariadbd] option group is primarily supported for backward compatibility. You should rename such option groups to [mariadbd-safe] in MariaDB installations to prevent breakage in the future if this compatibility is removed.

mariadbd-safe also reads options from the following server option groups from option files:

For example, if you specify the log_error option in a server option group in an option file, like this:

[mariadb]
log_error=error.log

Then mariadbd-safe will also use this value for its own --log-error option:

Configuring the Open Files Limit

When using mariadbd-safe, the system's open files limit can be changed by providing the --open-files-limit option either on the command-line or in an option file. For example:

[mariadbd-safe]
open_files_limit=4294967295

The option value is passed to ulimit -n. Note that you need to start mariadbd-safe as root for this to work properly. However, you can't currently set this to unlimited. See MDEV-18410 about that.

When mariadbd-safe starts mariadbd, it also uses this option to set the value of the open_files_limit system variable for mariadbd.

Configuring the Core File Size

When using mariadbd-safe, if you would like to enable core dumps, the system's core file size limit can be changed by providing the --core-file-size option either on the command-line or in an option file. For example:

[mariadbd-safe]
core_file_size=unlimited

The option value is passed to ulimit -c. Note that you need to start mariadbd-safe as root for this to work properly.

Configuring MariaDB to Write the Error Log to Syslog

When using mariadbd-safe, if you would like to redirect the error log to the syslog, then that can easily be done by using the --syslog option. mariadbd-safe redirects two types of log messages to the syslog--its own log messages, and log messages for mariadbd.

• mariadbd-safe configures its own log messages to go to the daemon syslog facility. The log level for these messages is either notice or error, depending on the specific type of log message. The default tag is mariadbd-safe.

• mariadbd-safe also configures the log messages for mariadbd to go to the daemon syslog facility. The log level for these messages is error. The default tag is mariadbd.

Sometimes it can be helpful to add a suffix to the syslog tag, such as if you are running multiple instances of MariaDB on the same host. To add a suffix to each syslog tag, use the --syslog-tag option.

Specifying mariadbd

By default, mariadbd-safe tries to start an executable named mariadbd.

You can also specify another executable for mariadbd-safe to start instead of mariadbd by providing the --mariadbd or --mariadbd-version options either on the command-line or in an option file.

By default, it will look for mariadbd in the following locations in the following order:

• $BASEDIR/libexec/mysqld
• $BASEDIR/sbin/mysqld
• $BASEDIR/bin/mysqld
• $PWD/bin/mysqld
• $PWD/libexec/mysqld
• $PWD/sbin/mysqld
• @libexecdir@/mysql

Where $BASEDIR is set by the --basedir option, $PWD is the current working directory where mariadbd-safe was invoked, and @libexecdir@ is set at compile-time by the INSTALL_BINDIR option for cmake.

You can also specify where the executable is located by providing the --ledir option either on the command-line or in an option file.

Specifying datadir

By default, mariadbd-safe will look for the datadir in the following locations in the following order:

• $BASEDIR/data/mysql
• $BASEDIR/data
• $BASEDIR/var/mysql
• $BASEDIR/var
• @localstatedir@

Where $BASEDIR is set by the --basedir option, and @localstatedir@ is set at compile-time by the INSTALL_MYSQLDATADIR option for cmake.

You can also specify where the datadir is located by providing the --datadir option either on the command-line or in an option file.

Logging

When you use mariadbd-safe to start mariadbd, mariadbd-safe logs to the same destination as mariadbd.

mariadbd-safe has several log-related options:

• --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 provided, then the default is --skip-syslog.

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

mariadbd-safe also writes notices to stdout and errors to stderr.

Editing mariadbd-safe

mariadbd-safe is a sh script, so if you need to change its behavior, then it can easily be edited. However, you should not normally edit the script. A lot of behavior can be changed by providing options either on the command-line or in an option file.

If you do edit mariadbd-safe, then you should be aware of the fact that a package upgrade can overwrite your changes. If you would like to preserve your changes, be sure to have a backup.

NetWare

On NetWare, mariadbd-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 mariadbd, monitors it, and restarts it if it terminates in error.
5. Sends error messages from mariadbd to the host_name.err file in the data directory.
6. Sends mariadbd-safe screen output to the host_name.safe file in the data directory.

See Also

• How to increase max number of open files on Linux. This can be used to solve issues like this warning from mariadbd: Changed limits: max_open_files: 1024 (requested 5000)"
• mariadbd Options
• systemd