Sync Mode is required for maximum protection modes

1. Database crashes if the async mode is set for the maximum protection mode. Minimum requirements for setting the maximum protection mode is sync,affirm.

[oracle@ol6-112-rac1 trace]$ sqlplus / as sysdba

SQL*Plus: Release 12.1.0.1.0 Production on Tue Jun 24 12:33:52 2014

Copyright (c) 1982, 2013, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup mount
ORACLE instance started.

Total System Global Area 1068937216 bytes
Fixed Size                  2296576 bytes
Variable Size             671089920 bytes
Database Buffers          390070272 bytes
Redo Buffers                5480448 bytes
Database mounted.
SQL> select name,open_mode,protection_mode from v$database;

NAME      OPEN_MODE            PROTECTION_MODE
--------- -------------------- --------------------
NEW12CDB  MOUNTED              MAXIMUM PROTECTION

SQL> show parameter log_archive_dest_3

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest_3                   string      SERVICE=ol6rac2  db_unique_nam
                                                 e=ol6rac2 async lgwr compressi
                                                 on=enable max_failure=4 reopen
                                                 =8
log_archive_dest_30                  string
log_archive_dest_31                  string
SQL> alter database open;
alter database open
*
ERROR at line 1:
ORA-03113: end-of-file on communication channel
Process ID: 18954
Session ID: 7 Serial number: 5

Alert log:-
==========
Starting background process ARC1
LGWR: Primary database is in MAXIMUM PROTECTION mode
LGWR: Destination LOG_ARCHIVE_DEST_3 is using asynchronous network I/O
LGWR: Destination LOG_ARCHIVE_DEST_1 is not serviced by LGWR
LGWR: Minimum of 1 synchronous standby database required
Errors in file /u01/app/orcl/oracle/diag/rdbms/ol6rac1/new12cdb/trace/new12cdb_lgwr_18928.trc:
ORA-16072: a minimum of one standby database destination is required
ARC1 started with pid=23, OS id=18972
USER (ospid: 18928): terminating the instance due to error 16072
System state dump requested by (instance=1, osid=18928 (LGWR)), summary=[abnormal instance termination].
System State dumped to trace file /u01/app/orcl/oracle/diag/rdbms/ol6rac1/new12cdb/trace/new12cdb_diag_18920.trc
Dumping diagnostic data in directory=[cdmp_20140624123440], requested by (instance=1, osid=18928 (LGWR)), summary=[abnormal instance termination].
Instance terminated by USER, pid = 18928

2.After changing the async to sync ,the database is able to open without any issues.

[oracle@ol6-112-rac1 trace]$ sqlplus / as sysdba

SQL*Plus: Release 12.1.0.1.0 Production on Tue Jun 24 12:37:03 2014

Copyright (c) 1982, 2013, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup mount
ORACLE instance started.

Total System Global Area 1068937216 bytes
Fixed Size                  2296576 bytes
Variable Size             671089920 bytes
Database Buffers          390070272 bytes
Redo Buffers                5480448 bytes
Database mounted.
SQL> show parameter log_archive_dest_3

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest_3                   string      SERVICE=ol6rac2  db_unique_nam
                                                 e=ol6rac2 async lgwr compressi
                                                 on=enable max_failure=4 reopen
                                                 =8
log_archive_dest_30                  string
log_archive_dest_31                  string
SQL> alter system set log_archive_dest_3='SERVICE=ol6rac2  db_unique_name=ol6rac2 sync lgwr compression=enable max_failure=4 reopen=8';

System altered.

SQL> select name,open_mode,protection_mode,database_role from v$database;

NAME      OPEN_MODE            PROTECTION_MODE      DATABASE_ROLE
--------- -------------------- -------------------- ----------------
NEW12CDB  MOUNTED              MAXIMUM PROTECTION   PRIMARY

SQL> alter database open;

Database altered.