Sorry, forgot to post an example for you - here's how one of my sites is setup. My DB's are all on another host than the slash server.

my $virtual1 = {
              'siteid' => {
                                    'database' => 'siteiddb',
                                    'password' => 'typeyourpasswordhere',
                                    'attributes' => {},
                                    'port' => '',
                                    'username' => 'siteuser',
                                    'host' => '',
                                    'driver' => 'mysql',
                                    'connect' => 'DBI:mysql:database=siteiddb$

In this example, the site is told to connect to for the database. That's my db server. the user, 'siteuser' will need perms in mysql that tell it to allow connections for that user FROM the ip of your slash server. Let me know if you need an example of that.