Skip navigation links
MySQL 3.23, 4.0, 4.1 Reference Manual :: 7 Optimization :: 7.6 Disk Issues :: 7.6.1 Using Symbolic Links :: 7.6.1.3 Using Symbolic Links for Databases on Windows
8 Language Structure »
Section Navigation      [Toggle]

7.6.1.3. Using Symbolic Links for Databases on Windows

Beginning with MySQL 3.23.16, the mysqld-max and mysql-max-nt servers for Windows are compiled with the -DUSE_SYMDIR option. This enables you to put a database directory on a different disk by setting up a symbolic link to it. This is similar to the way that symbolic links work on Unix, although the procedure for setting up the link is different.

It is necessary to define USE_SYMDIR explicitly only before MySQL 4.0; for mysqld-max and mysql-max-nt, you can enable symbolic links by using the --symbolic-links option. As of MySQL 4.0, symbolic links are enabled by default for all Windows servers. If you do not need them, you can disable them with the --skip-symbolic-links option.

On Windows, create a symbolic link to a MySQL database by creating a file in the data directory that contains the path to the destination directory. The file should be named db_name.sym, where db_name is the database name.

Suppose that the MySQL data directory is C:\mysql\data and you want to have database foo located at D:\data\foo. Set up a symlink using this procedure:

  1. Make sure that the D:\data\foo directory exists by creating it if necessary. If you already have a database directory named foo in the data directory, you should move it to D:\data. Otherwise, the symbolic link will be ineffective. To avoid problems, make sure that the server is not running when you move the database directory.

  2. Create a text file C:\mysql\data\foo.sym that contains the path name D:\data\foo\.

    Note

    The path name to the new database and tables should be absolute. If you specify a relative path, the location will be relative to the foo.sym file.

After this, all tables created in the database foo are created in D:\data\foo.

The following limitations apply to the use of .sym files for database symbolic linking on Windows:

  • The symbolic link is not used if a directory with the same name as the database exists in the MySQL data directory.

  • The --innodb_file_per_table option cannot be used.

  • If you run mysqld as a service, you cannot use a mapped drive to a remote server as the destination of the symbolic link. As a workaround, you can use the full path (\\servername\path\).


User Comments

Posted by Ivan D on April 6 2008 9:47pm[Delete] [Edit]

You can also Mount any NTFS Partition to an empty folder with the disk management tool. In this case your Database folder.

For step-by-step instructions on Mounting a partition:
http://support.microsoft.com/kb/307889

Add your own comment.