The PAM authentication plugin must be located in the MySQL
plugin directory (the directory named by the
plugin_dir system variable).
If necessary, set the value of
plugin_dir at server startup
to tell the server the location of the plugin directory.
To enable the plugin, start the server with the
--plugin-load option. For
example, put the following lines in your
my.cnf file. If object files have a
suffix different from
.so on your system,
substitute the correct suffix.