Hi Dingi,
You can do it from the configure database logging option of the databases menu under the control center.
OR You can customize the sample commands below.
CONNECT TO SAMPLE
QUIESCE DATABASE IMMEDIATE FORCE CONNECTIONS;
UNQUIESCE DATABASE;
CONNECT RESET;
UPDATE DB CFG FOR SAMPLE USING logretain ON userexit ON logprimary 3 logsecond 2 logfilsiz 250;
BACKUP DATABASE SAMPLE TO "E:\ARCHLOGS\" WITH 2 BUFFERS BUFFER 1024 PARALLELISM 1 WITHOUT PROMPTING;
Please also read on backups to get a better picture.
HTH