Provided by: mysql-server-5.5_5.5.22-0ubuntu1_amd64 bug


       mysqld_safe - MySQL server startup script


       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. A description 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. 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, “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 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 MySQL 5.5 installations.

       mysqld_safe supports the following options. It also reads option files and supports the
       options for processing them described at Section, “Command-Line Options that
       Affect Option-File Handling”.

       ·   --help

           Display a help message and exit.

       ·   --basedir=path

           The path to the MySQL 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.

       ·   --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.

       ·   --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. See Section 5.2.2, “The Error Log”.

       ·   --malloc-lib=[lib_name]

           The name of the library to use for memory allocation instead of the system malloc()
           library. Any library can be used by specifying its path name, but there is a shortcut
           form to enable use of the tcmalloc library that is shipped with binary MySQL
           distributions for Linux in MySQL 5.5.

           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

           ·   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.

           ·   If the option is given as --malloc-lib=tcmalloc, mysqld_safe looks for a tcmalloc
               library in /usr/lib and then in the MySQL pkglibdir location (for example,
               /usr/local/mysql/lib or whatever is appropriate). 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.

           ·   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.
               Linux users can use the included in binary packages by
               adding these lines to the my.cnf file:


               Those lines also suffice for users on any platform who have installed a tcmalloc
               package in /usr/lib. To use a specific tcmalloc library, specify its full path
               name. Example:


           ·   --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 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.

           ·   --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-defaults

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

           ·   --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

           ·   --pid-file=file_name

               The path name of the process ID file.

           ·   --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

           ·   --socket=path

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

           ·   --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 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

               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:

               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.

           Beginning with MySQL 5.5.21, mysqld_safe tries to use the sleep and date system
           utilities to determine how many times it has attempted to start this second, and—if
           these are present and this is greater than 5 times—is forced to wait 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

           ·   --syslog: Write error messages to syslog on systems that support the logger

           ·   --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

           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 MySQL in the future, so you should
           make a copy of your edited version that you can reinstall.


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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


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