First, you should a new empty 'radius' database in MySQL and login user with permissions to that database. You could of course call the database and the user anything you like but we'll stick to 'radius' for both for the purposes of this discussion
Next up, you need to create the schema for the database. There is a file which describes this and is actually a SQL script file. It can be found at /src/modules/rlm_sql/drivers/rlm_sql_mysql/db_mysql.sql where you untar'd FreeRadius. This is the bit that, at least at the time I originally wrote these notes, wasn't really documented anywhere and was the thing most people seemed to be asking.
How you run that script is up to you and how you like to admin MySQL. The easiest way is to:
mysql -uroot -prootpass radius < db_mysql.sql
...where 'root' and 'rootpass' are your mysql root name and password respectively.
Uwe, Thanks for your answer. About the empty database 'radius' I had already done that. This morning I ran the script 'db_mysql.sql' you talked about. Now I can see the tables in my database radius but I still have the same segmentation fault error. I have reconfigured, recompiled (with make clean) and reinstalled. That didn't help. Do you have any other ideas? Thanks for your help, --Vicky