Resizing Oracle Redo Log Groups in RAC

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How to Resizing Oracle Redo Log Groups in RAC

Resizing Oracle's redo log groups is performed in 2 Steps.
Step1> Add new the redo log groups with expected size.
Step2> Drop the old redo log groups.

In this post I will resize the redo log groups of size 50MB to 2GB in a 2Node RAC cluster

Find the redo log's current status, size and member

ORCL1> select group#,thread#,status, bytes/1024/1024 "size in MB" from v$log;
    GROUP#    THREAD# STATUS               size in MB
---------- ---------- -------------------- ----------
         1          1 CURRENT                      50
         2          1 INACTIVE                     50
         3          2 CURRENT                      50
         4          2 INACTIVE                     50
4 rows selected.

ORCL1>  select group#, member  from v$logfile order by 1;
    GROUP# MEMBER
---------- --------------------------------------------------
         1 +DATA/ORCL/ONLINELOG/group_1.1225.984754235
         1 +RECO/ORCL/ONLINELOG/group_1.40899.984754235
         2 +RECO/ORCL/ONLINELOG/group_2.40649.984754235
         2 +DATA/ORCL/ONLINELOG/group_2.1013.984754235
         3 +DATA/ORCL/ONLINELOG/group_3.975.984754715
         3 +RECO/ORCL/ONLINELOG/group_3.11020.984754715
         4 +RECO/ORCL/ONLINELOG/group_4.8745.984754715
         4 +DATA/ORCL/ONLINELOG/group_4.1326.984754715
8 rows selected.

Add new Redo Log Groups of 2 GB

Note:- If you are using file system mount point to store redo logs specify the full name of the logfile instead of just diskgroups
SQL>alter database add logfile thread 1
group 5 ('+DATA','+RECO') size 2048M,
group 6 ('+DATA','+RECO') size 2048M;
Database altered.
SQL>alter database add logfile thread 2
group 7 ('+DATA','+RECO') size 2048M,
group 8 ('+DATA','+RECO') size 2048M;
Database altered.

Drop Old Redo Log Groups

SQL>alter database drop logfile group 1;
Database altered.SQL>alter database drop logfile group 2;
Database altered.
SQL>alter database drop logfile group 3;
Database altered.
SQL>alter database drop logfile group 4;
Database altered.