edit the mysql section in the services.conf ... as an identified oper with Services Admin access or higher type: /msg operserv set sql on
then type: /msg operserv update
This assumes you have mysql installed, running and services is compiled to use it.
NOTE: Anope doesn't use mysql in a live environment, it writes to sql on update and can load from sql only, meaning the FFF databases will still be your live db's!