Drupal Multisite Configuration via Subdirectories

If you have a basic Drupal web siteinstalled in the root directory on your webserver and you want to set up a new website in a subdirectory, with its own themes and module settings, here is how I do it.

Applies to Drupal 6.X:

1. Back-up everything: your database (e.g., using the Drupal Backup and Migrate module) and your Drupal files.
2. Create a folder on your local PC with a name something like /mysite.com.mynewsubsite. [note the weird syntax!]
3. Using FTP, download the entire contents of your webserver's /sites/default directory into the directory you just created.
4. In the settings.php file in the new directory, change the database prefix to something suitable for your subsite, for example:
   
   $db_prefix = 'mynewsubsite_';
    
5. Upload the whole /mysite.com.mynewsubsite directory (or whatever you have called it) to the webserver's /sites directory. You should now have a directory structure on your webserver that looks like this:
   
   www.mysite.com/sites/default/
   www.mysite.com/sites/mysite.com.mynewsubsite/
   
   
6. Create a text file called makesymlink.php containing this text:
   
   <?php
symlink(".", "newsubsite");
print "Done";
?>
7. Upload makesymlink.php to the root directory of your webserver.
8. Run makesymlink.php by going to http://www.mysite.com/makesymlink.php in your browser. The script will run and "Done" should be displayed in your browser.
9. Delete makesymlink.php from your webserver.
10. Go to www.mysite.com/newsubsite/install.php in your browser.
11. Now you can set up the new site.