ORA-01623: log 31 is current log for instance RACTEST3 (thread 3) – cannot drop

Three nodes RAC database was migrated to two nodes RAC database, while trying to drop online redo logs of thread 3,  the errors are as below:

SQL> alter database drop logfile group 31;
alter database drop logfile group 31
*
ERROR at line 1:
ORA-01623: log 31 is current log for instance RACTEST3 (thread 3) - cannot drop
ORA-00312: online log 31 thread 3: '+DATA1/ractest/onlinelog/group_31.409.924815767'
ORA-00312: online log 31 thread 3: '+FRA/ractest/onlinelog/group_31.262.924815769'

SOLUTION

Disable thread 3 by :

SQL> alter database disable thread 3;

Database altered.

Then drop the redo logs successfully.

SQL> alter database drop logfile group 31;

Database altered.

SQL> alter database drop logfile group 32;

Database altered.

SQL> alter database drop logfile group 33;
Database altered.

...
..
.