I would like to know if it's possible to operate different databases on different filesystem locations.

Background: we are a hosting service, which hosts mysql, web, and smtp to it's customer, but all our services (sql, smtp, http) are located in a different place. We are going to assign a single logical volume to a customer, which will accommodate the customer's mailing, weppages and (hopefully) sql database. Web pages and mailing are already covered, but I am not able to find a configuration setting which would enable me to specify the location of a database (the directory where mysql stores the DB).

Let me please highlight, the target here is to relocate different databases to different locations in the filesystem, not moving them from a single place to an another (single) place. 

Also please do not bother answering with soft and hard symbolic links. ;)

Thanks