Security log Activate

Dear Team,

I wanted to enable audit log permanently,I have set the following three parameter ,and taken a restart.

rsau/enable  1

rsau/max_diskspace/local  2048M

rsau/max_diskspace/per_file   512M

But still i cant see log in sm20...What else need to be done ....Whether after Maintaining the parameter also i need to activate from sm19.

RK