Hi,

I think you have three loggroups with one member each. Am I right? You have to multiplex the redo log files with more members on another device. In this case you don't have to shutdown the database.

ALTER DATABASE ADD LOGFILE MEMBER
'another device:/some directory/redo01_2.log' TO GROUP 1;
ALTER DATABASE ADD LOGFILE MEMBER
'another device:/some directory/redo02_2.log' TO GROUP 2;
ALTER DATABASE ADD LOGFILE MEMBER
'another device:/some directory/redo03_2.log' TO GROUP 3;

Good luck!