Interbase 6 CS on linux, DB-File-Locations?

Hi,

I'm currently playing around with Interbase 6 CS on our linux box
running under SuSE 6.4.

Everything works fine, except that all files containig the databases are
stored in the root ("/") directory as long as I don't specify a full
pathname when I create the database.

Is there something like a "DATABASE_ROOT" variable or configuration
option that defines the directory where the databses are stored?

Thanks

Oliver