Adding Redo log file in Oracle Database

Adding a redo log file set

ALTER DATABASE
  ADD LOGFILE
   ('/data/disk77/log3a.rdo', '/data/disk78/log3b.rdo')
   SIZE 500K;


ALTER DATABASE ADD LOGFILE MEMBER
  '/data/disk77/log3a.rdo' TO GROUP 1, 
  '/data/disk78/log3b.rdo' TO GROUP 2;


ALTER DATABASE
  ADD LOGFILE
   '/data2/oradata/MARSH/redo14.log'
   SIZE 10M;


select group#,thread#,archived,status from v$log ;

select * from v$logfile ;

ALTER SYSTEM SWITCH LOGFILE ;

ALTER DATABASE DROP LOGFILE '/data/OraHome1/oradata/TEST/redo01.log'
ALTER DATABASE DROP LOGFILE '/data/OraHome1/oradata/TEST/redo02.log'