I have been running FreeRADIUS 2.x using a custom Microsoft SQL Server database using UnixODBC. I compiled version 3.0.0 on a new server, read the migration documentation, and configured freeTDS and UnixODBC. I verified that UnixODBC was working using the iSQL tool, connecting to the freeradius datasource. I copied mods-available/sql to mods-enabled/sql and configured it as such: sql { driver="rlm_sql_unixodbc" dialect="mssql" server = "freeradius" login = "xxx" password = "xxx" radius_db = "radiusdb" } In addition, I specified the tables and left the other values as default. I then configured my queries.conf file in the mssql directory. When starting FreeRADIUS in debug, the following lines are output prior to the segmentation fault: sql { driver = "rlm_sql_unixodbc" server = "freeradius" port = "" login = "xxx" password = "xxx" radius_db = "radiusdb" read_groups = yes read_clients = no delete_stale_sessions = yes . . . } (sql): Driver rlm_sql_unixodbc (module rlm_sql_unixodbc) loaded and linked. (sql): Attempting to connect to database "radiusdb" rlm_sql (sql): Initialising connection pool pool { start = 5 min = 4 max = 10 spare = 3 uses = 0 lifetime = 0 cleanup_delay = 5 idle_timeout = 60 spread = no } (sql): Opening additional connection (0) Segmentation fault If I modify sql and set the driver = "rlm_sql_null" then FreeRADIUS starts up without error. Any ideas? Grant Spradling