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
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:
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.
Display a help message and exit.
The path to the MariaDB installation directory.
The size of the core file that mysqld should be able to create.
The option value is passed to ulimit -c.
Script to call in the event of mysqld crashing.
The path to the data directory.
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.
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
Flush and purge buffers/caches before starting the server.
If mysqld_safe cannot find the server, use this option to
indicate the path name to the directory where the server is
Write the error log to the given file.
Preload shared library lib if available.
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.
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
Use the nice program to set the server´s scheduling priority to
the given value.
Exit after starting mysqld.
Do not read any option files. This must be the first option on
the command line if it is used.
Exit after starting mysqld.
Run mysqld with its memory interleaved on all NUMA nodes.
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!
The path name of the process ID file.
Directory for client-side plugins.
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.
Do not try to kill stray mysqld processes at startup. This option
works only on Linux.
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.
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.
Set the TZ time zone environment variable to the given option
value. Consult your operating system documentation for legal time
zone specification formats.
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
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
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
· 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
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
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
· --log-error=file_name: Write error messages to the named error
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
On NetWare, mysqld_safe is a NetWare Loadable Module (NLM) that is
ported from the original Unix shell script. It starts the server as
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
5. Sends error messages from mysqld to the host_name.err file in the
6. Sends mysqld_safe screen output to the host_name.safe file in the
Copyright 2007-2008 MySQL AB, 2008-2010 Sun Microsystems, Inc.,
2010-2015 MariaDB Foundation
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Information about the project can be found at ⟨http://mariadb.org/⟩.
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MariaDB 10.1 14/12/2015 MYSQLD_SAFE(1)