Online Redo Log File Management In 11gR2 RAC/ASM.

SQL> select GROUP#,THREAD#  from v$log;

    GROUP#    THREAD#
---------- ----------
         1          1
         2          1
         3          2
         4          2


Here Thread 1 refers to Node 1 and Thread 2 refers to Node 2.

SQL> alter database add logfile thread 1 group 5 ('+DATA') size 50M;

Database altered.

SQL> alter database add logfile thread 1 group 6 ('+DATA') size 50M;

Database altered.

SQL> alter database add logfile thread 2 group 7 ('+DATA') size 50M;

Database altered.

SQL> alter database add logfile thread 2 group 8 ('+DATA') size 50M;

Database altered.


SQL> select THREAD#,GROUP# from v$log order by THREAD#;

   THREAD#     GROUP#
---------- ----------
         1          1
         1          6
         1          5
         1          2
         2          7
         2          8
         2          3
         2          4

8 rows selected.

To Add logfile member:

SQL> alter database add logfile member '+DATA' to group 1;

Database altered.

SQL> select group#,member from v$logfile order by group#;


    GROUP#
----------
MEMBER
---------------------------------------------------------------------------------------------------
         1
+DATA/orcl/onlinelog/group_1.261.823159585

         1
+FRA/orcl/onlinelog/group_1.257.823159591

         1
+DATA/orcl/onlinelog/group_1.277.823782961

         2
+DATA/orcl/onlinelog/group_2.262.823159597

         2
+FRA/orcl/onlinelog/group_2.258.823159599

         3
+DATA/orcl/onlinelog/group_3.266.823160637

         3
+FRA/orcl/onlinelog/group_3.259.823160641

         4
+FRA/orcl/onlinelog/group_4.260.823160649

         4
+DATA/orcl/onlinelog/group_4.267.823160645

         5
+DATA/orcl/onlinelog/group_5.273.823782521

         6
+DATA/orcl/onlinelog/group_6.274.823782539

         7
+DATA/orcl/onlinelog/group_7.275.823782599

         8
+DATA/orcl/onlinelog/group_8.276.823782615


13 rows selected.