Dropping online redo logs

If you want to move redo logs to another filesystem without shutting down the database you can
create new groups on the new filesystem and drop the old groups.

1. Create new online redo log groups

SQL> ALTER DATABASE ADD LOGFILE ('/path2redo/redo4a.log') SIZE 100M;
SQL> ALTER DATABASE ADD LOGFILE ('/path2redo/redo5a.log') SIZE 100M;
SQL> ALTER DATABASE ADD LOGFILE ('/path2redo/redo6a.log') SIZE 100M;

2. Switch log file as many times as needed for the new group to become the current one

SQL> alter system switch logfile;

3. Do checkpoint

SQL> alter system checkpoint;

4. Confirm that the old groups are inactive

SQL> select * from v$log;

    GROUP#    THREAD#  SEQUENCE#      BYTES    MEMBERS ARC STATUS           FIRST_CHANGE#
FIRST_TIM
---------- ---------- ---------- ---------- ---------- --- ---------------- -------------
---------
         1          1          7  104857600          1 NO  INACTIVE                262831
13-JUN-08
         2          1          8  104857600          1 NO  INACTIVE                271668
13-JUN-08
         3          1          9  104857600          1 NO  CURRENT                 276366
13-JUN-08
...


5. Drop the old groups

SQL> ALTER DATABASE DROP LOGFILE GROUP 1;

6. If not using ASM files have to be removed manually; remove the files for redo log groups
that have been dropped

rm /path2oldredo/redo1a.log