MYSQLD_SAFE(1) MySQL Database System MYSQLD_SAFE(1)
mysqld_safe - MySQL server startup script
safe_mysqld - MySQL server startup script
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. NetWare-specific behaviors are listed later in this section.
To preserve backward compatibility with older versions of MySQL,
MySQL binary distributions still include safe_mysqld as a symbolic
link to mysqld_safe. However, you should not rely on this because
it is removed as of MySQL 5.1.
By default, mysqld_safe before MySQL 5.0.27 tries to start an
executable named mysqld-max if it exists, and mysqld otherwise. Be
aware of the implications of this behavior:
? On Linux, the MySQL-Max RPM relies on this mysqld_safe behavior.
The RPM installs an executable named mysqld-max, which causes
mysqld_safe to automatically use that executable rather than mysqld
from that point on.
? If you install a MySQL-Max distribution that includes a server
named mysqld-max, and then upgrade later to a non-Max version of
MySQL, mysqld_safe will still attempt to run the old mysqld-max
server. If you perform such an upgrade, you should manually remove
the old mysqld-max server to ensure that mysqld_safe runs the new
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] group of an option file. See Section 18.104.22.168, "Using
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 will find and use the
For backward compatibility, mysqld_safe also reads [safe_mysqld]
sections, although you should rename such sections to [mysqld_safe] in
MySQL 5.0 installations.
mysqld_safe supports the following options. It also reads option files
and supports the options for processing them described at
Section 22.214.171.124.1, "Command-Line Options that Affect Option-File
Display a help message and exit. (Added in MySQL 5.0.3)
(NetWare only) On NetWare, mysqld_safe provides a screen presence.
When you unload (shut down) the mysqld_safe NLM, the screen does
not by default go away. Instead, it prompts for user input:
*<NLM has terminated; Press any key to close the screen>*
If you want NetWare to close the screen automatically instead, use
the --autoclose option to mysqld_safe.
The path to the MySQL installation directory.
The size of the core file that mysqld should be able to create. The
option value is passed to ulimit -c.
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. As of MySQL 5.0.6, 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
If mysqld_safe cannot find the server, use this option to indicate
the path name to the directory where the server is located.
Write the error log to the given file. See Section 5.2.1, "The
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 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.
Use the nice program to set the server?s scheduling priority to the
Do not read any option files. This must be the first option on the
command line if it is used.
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.
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
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 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 2.7,
"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
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
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.
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
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
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
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For more information, please refer to the MySQL Reference Manual, which
may already be installed locally and which is also available online at
Oracle Corporation (http://dev.mysql.com/).
MySQL 5.0 12/16/2011 MYSQLD_SAFE(1)