SWITCH OVER TO DISASTER RECOVERY DATABASE

Oracle switchover may be needed as an IT procedure to check the validity of the DR,For maintenance purpose or any other reasons. The following procedure might help to switchover to the Disaster Recovery Site in any case. Since switchover is planned unlike failover, we need to do the following precaution actions first.

PRECAUTIONS !

• Make sure that the full database backup is taken for safety just in case anything goes wrong during the switch over process and validate the backup taken.
• Make sure the backup encompasses all important files besides the data files and the archive logs like backup of control file, parameter files, etc.

INFORMATION 

primary database name PROD

primary database instance name PROD1

standby database name PROD

standby database instance name PRODSBY

production machine name RAC1

standby machine name RACSBY
Steps that has to be followed in the process of Switching over to Standby database


 1. Verify that both the primary and standby parameter files support role transition.

$ export ORACLE_SID=PROD1

$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on Mon May 21 07:46:45 2012
Copyright (c) 1982, 2009, Oracle.  All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
Data Mining and Real Application Testing options
THE INSTANCE NAME IS  PROD1
SQL> select name,open_mode,database_role from v$database;
NAME      OPEN_MODE            DATABASE_ROLE
---------       --------------------         ----------------
PROD        READ WRITE           PRIMARY
$ export ORACLE_SID=PRODSBY
$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on Mon May 21 07:46:45 2012
Copyright (c) 1982, 2009, Oracle.  All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
Data Mining and Real Application Testing options
THE INSTANCE NAME IS  PRODSBY
SQL> select name,open_mode,database_role from v$database;
NAME      OPEN_MODE            DATABASE_ROLE
---------       --------------------         ----------------
PROD        READ WRITE           PHYSICAL STANDBY
2. Verify that there is network connectivity between the primary and standby
locations.
$ ping RAC1 from standby machine OS and should reply, alternatively ip can be used.
$ ping RACSBY from production machine OS again should reply

3. Each location in the Data Guard configuration should have connectivity through Oracle Net to the primary database and to all associated standby databases. This can be checked by
tnsping  PROD ..........from the standby
nslookup RAC1 ........from the standby
4. Convert the primary database to the new standby
 alter database commit to switchover to physical standby;
5. Shutdown the former primary and mount as a standby database:
shutdown immediate
startup nomount
alter database mount standby database;
6. Defer the remote archive destination on the old primary
alter system set log_archive_dest_state_2=defer;
7. Verify that the physical standby can be converted to the new primary
select switchover_status from v$database;
8. Convert the physical standby to the new primary
alter database commit to switchover to primary;
9. Shutdown and startup the new primary
Connect as ‘oracle’ user and’ PRODSBY’ ORACLE_SID
shutdown immediate
startup
10. Enable remote archiving on the new primary to the new standby
alter system set log_archive_dest_state_2=enable;
11. Start managed recover on the new standby database
recover managed standby database disconnect;
12. Check the gap between the new standby and new primary