Configuring Oracle for Recoverability

1. turn on ARCHIVELOG MODE
2. Config Fast (Flash) Recovery Area
3. Set retention policy

Turn on ARCHIVELOG MODE

It is easy to do this using Oracle Enterprise Manager under Availability -> Recovery Settings. The database instance will have to be restarted for this.

To check whether the DB is being run in ARCHIVELOG mode you should type

SQL> select log_mode from v$database;

Otherwise following steps should be taken:
1. SHUTDOWN the database
2. make cold database backup
3. Edit the initialization parameter file to include the initialization parameters that specify the destinations for the archived redo log files

To check those parameters you should just type

SQL> show parameter log_archive_dest_1;

or you can type some other parameter

LOG_ARCHIVE_DEST_1 = ‘LOCATION=/disk1/arc’
LOG_ARCHIVE_DEST_2 = ‘LOCATION=/disk2/arc’
LOG_ARCHIVE_FORMAT = ‘orcl_%t_%s_%r.arc’

Specifying “USE_DB_RECOVERY_FILE_DEST” parameter as a log archive destination, means that we want our archived log files to be saved in the Fast (Flash) Recovery Area.

4. STARTUP MOUNT the database
5. turn on archiving and turn on the database
ALTER DATABASE ARCHIVELOG;
ALTER DATABASE OPEN;
6. after archiving was turned on, control file was changed so we have to backup the database including control file again. Any previously taken backups are no longer useful.
SHUTDOWN the database
7. BACKUP the database

Configure Fast (Flash) Recovery Area

The following initialization parameters should be set
db_recovery_file_dest = ‘d:\oracle\fra’;
db_recovery_file_dest_size = 4G;

We can see the current size with the following command
SQL> show parameter db_recovery;

Set retention policy

This is RMAN setting to specify how long to keep backups. It is possible to specify how many full backups you want to keep

RMAN> configure retention policy to redundancy 2;

or you can set for how many days you want to keep all the backups in that period

RMAN> configure retention policy to recovery window of 7 days;

Eventually you can put back the default settings by typing

RMAN> configure retention policy to none:

which will be same as redundancy 1 keeping only the last backup.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: