Flashback area not enough, leading archived failed

1) flashback area not enough, leading archived failed
1@@@@ Example I do too much dml operation with huge redo logs. So...
[oracle@station78 ~]$ sqlplus / as sysdba;
Connected to an idle instance.
SYS@ocm> startup
ORACLE instance started.

Total System Global Area  524288000 bytes
Fixed Size            2022016 bytes
Variable Size          159384960 bytes
Database Buffers      356515840 bytes
Redo Buffers            6365184 bytes
Database mounted.
ORA-16038: log 1 sequence# 53 cannot be archived
ORA-19809: limit exceeded for recovery files
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/ocm/redo01.log'

@@@Cat the alert_log:
......
ARC0: Archiving not possible: No primary destinations
ARC0: Failed to archive thread 1 sequence 53 (4)
ARCH: Archival stopped, error occurred. Will continue retrying
Thu Jan 10 15:50:26 2013
ORACLE Instance ocm - Archival Error
Thu Jan 10 15:50:26 2013
ORA-16014: log 1 sequence# 53 not archived, no available destinations
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/ocm/redo01.log'
Thu Jan 10 15:50:26 2013
Errors in file /u01/app/oracle/admin/ocm/bdump/ocm_arc0_17738.trc:
ORA-16014: log 1 sequence# 53 not archived, no available destinations
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/ocm/redo01.log'
Thu Jan 10 15:51:01 2013
......


SYS@ocm> show parameter recovery
NAME                     TYPE     VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest             string     /u01/app/oracle/flash_recovery
                         _area
db_recovery_file_dest_size         big integer 2G
recovery_parallelism             integer     0

SYS@ocm> alter system set db_recovery_file_dest_size=5G ;
System altered.


@@@Cat the alert_log:
......
ALTER SYSTEM SET db_recovery_file_dest_size='5G' SCOPE=BOTH;
Thu Jan 10 15:51:10 2013
alter database open
Thu Jan 10 15:51:10 2013
Block change tracking file is current.
db_recovery_file_dest_size of 5120 MB is 40.45% used. This is a
user-specified limit on the amount of space that will be used by this
database for recovery-related files, and does not reflect the amount of
space available in the underlying filesystem or ASM diskgroup.
Thu Jan 10 15:51:11 2013
Thread 1 advanced to log sequence 56
Thread 1 opened at log sequence 56
  Current log# 1 seq# 56 mem# 0: /u01/app/oracle/oradata/ocm/redo01.log
Successful open of redo thread 1
Thu Jan 10 15:51:12 2013
MTTR advisory is disabled because FAST_START_MTTR_TARGET is not set
Thu Jan 10 15:51:13 2013
Archiver process freed from errors. No longer stopped
Thu Jan 10 15:51:13 2013
Starting background process CTWR
CTWR started with pid=22, OS id=18022
Block change tracking service is active.
Thu Jan 10 15:51:13 2013
SMON: enabling cache recovery
Thu Jan 10 15:51:13 2013
Successfully onlined Undo Tablespace 1.
Thu Jan 10 15:51:13 2013
SMON: enabling tx recovery
SMON: Parallel transaction recovery tried
Thu Jan 10 15:51:14 2013
Database Characterset is AL32UTF8
replication_dependency_tracking turned off (no async multimaster replication found)
Starting background process QMNC
QMNC started with pid=28, OS id=18034
Thu Jan 10 15:51:15 2013
Completed: alter database open
......


SYS@ocm> alter database open;
Database altered.