2.3.7. Creating an Option File
If you need to specify startup options when you run the server,
you can indicate them on the command line or place them in an
option file. For options that are used every time the server
starts, you may find it most convenient to use an option file to
specify your MySQL configuration. This is particularly true
under the following circumstances:
The installation or data directory locations are different
from the default locations (C:\Program
Files\MySQL\MySQL Server 5.1 and
C:\Program Files\MySQL\MySQL Server
5.1\data).
You need to tune the server settings.
When the MySQL server starts on Windows, it looks for options in
two files: the my.ini file in the Windows
directory, and the C:\my.cnf file. The
Windows directory typically is named something like
C:\WINDOWS or
C:\WINNT. You can determine its exact
location from the value of the WINDIR
environment variable using the following command:
C:\> echo %WINDIR%
MySQL looks for options first in the my.ini
file, and then in the my.cnf file. However,
to avoid confusion, it's best if you use only one file. If your
PC uses a boot loader where C: is not the
boot drive, your only option is to use the
my.ini file. Whichever option file you use,
it must be a plain text file.
You can also make use of the example option files included with
your MySQL distribution. Look in your install directory for
files such as my-small.cnf,
my-medium.cnf,
my-large.cnf, and
my-huge.cnf, which you can rename and copy
to the appropriate location for use as a base configuration
file.
An option file can be created and modified with any text editor,
such as Notepad. For example, if MySQL is installed in
E:\mysql and the data directory is in
E:\mydata\data, you can create an option
file containing a [mysqld] section to specify
values for the basedir and
datadir parameters:
[mysqld]
# set basedir to your installation path
basedir=E:/mysql
# set datadir to the location of your data directory
datadir=E:/mydata/data
Note that Windows pathnames are specified in option files using
(forward) slashes rather than backslashes. If you do use
backslashes, you must double them:
[mysqld]
# set basedir to your installation path
basedir=E:\\mysql
# set datadir to the location of your data directory
datadir=E:\\mydata\\data
On Windows, the MySQL installer places the data directory
directly under the directory where you install MySQL. If you
would like to use a data directory in a different location, you
should copy the entire contents of the data
directory to the new location. For example, if MySQL is
installed in C:\Program Files\MySQL\MySQL Server
5.1, the data directory is by default in
C:\Program Files\MySQL\MySQL Server
5.1\data. If you want to use
E:\mydata as the data directory instead,
you must do two things:
Move the entire data directory and all
of its contents from C:\Program Files\MySQL\MySQL
Server 5.1\data to
E:\mydata.
Use a --datadir option to specify the new
data directory location each time you start the server.
