RMAN Configuration

A complete high availability and disaster recovery strategy requires dependable data backup, restore, and recovery procedures. Oracle Recovery Manager (RMAN), a command-line and Enterprise Manager-based tool, is the Oracle-preferred method for efficiently backing up and recovering your Oracle database. RMAN is designed to work intimately with the server, providing block-level corruption detection during backup and restore. RMAN optimizes performance and space consumption during backup with file multiplexing and backup set compression, and integrates with Oracle Secure Backup and third party media management products for tape backup.

RMAN takes care of all underlying database procedures before and after backup or restore, freeing dependency on OS and SQL*Plus scripts. It provides a common interface for backup tasks across different host operating systems, and offers features not available through user-managed methods, such as parallelization of backup/recovery data streams, backup files retention policy, and detailed history of all backups.

Step 01: Create tablepsace to hold repository

#sqlplus sys/sys_password@orcl AS SYSDBA

SQL>  CREATE TABLESPACE "RMAN"
DATAFILE 'C:\oracle\product\10.2.0\oradata\orcl\RMAN.DBF' SIZE 6208K REUSE
AUTOEXTEND ON NEXT 64K MAXSIZE 32767M
EXTENT MANAGEMENT LOCAL
SEGMENT SPACE MANAGEMENT AUTO;

Step 02: Create user RMAN Schema owner for the backup and recovery using RMAN.

SQL>  CREATE USER rman IDENTIFIED BY rman
TEMPORARY TABLESPACE temp
DEFAULT TABLESPACE rman
QUOTA UNLIMITED ON rman;

Step 03: Grant recovery_catalog_owner to RMAN user

SQL>  GRANT connect, resource, recovery_catalog_owner TO rman;

Step 04: Now connect to the RMAN and Create Repository catalog

$rman catalog=rman/rman@orcl

Recovery Manager: Release 10.2.0.1.0 - Production on Wed Dec 16 19:55:32 2009

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

connected to recovery catalog database

RMAN> create catalog tablespace "RMAN";

recovery catalog created

Step 05: Register Database Each database to be backed up by RMAN must be registered

$rman catalog=rman/rman@orcl target=sys/oracle@orcl

Recovery Manager: Release 10.2.0.1.0 - Production on Wed Dec 16 20:01:00 2009

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

connected to target database: ORCL (DBID=1223903242)
connected to recovery catalog database

RMAN> register database;

database registered in recovery catalog
starting full resync of recovery catalog
full resync complete

RMAN> exit

Recovery Manager complete.

We have done!!!! The configuration of RMAN in our Database

Some Basic Parameter of RMAN

Retention Policy:

This instructs RMAN on the backups that are eligible for deletion. For example: A retention policy with redundancy 2 would mean that two backups - the latest and the one prior to that - should be retained. All other backups are candidates for deletion.

Default Device Type:

This can be "disk" or "sbt" (system backup to tape). We will backup to disk and then have our OS backup utility copy the completed backup, and other supporting files, to tape.

Control files Auto backup:

This can be set to "on" or "off". When set to "on", RMAN takes a backup of the control file AND server parameter file each time a backup is performed. Note that "off" is the default

Parallelism:

This tells RMAN how many server processes you want dedicated to performing the backups.

Device Type Format:

This specifies the location and name of the backup files. We need to specify the format for each channel. The "%U" ensures that Oracle appends a unique identifier to the backup file name. The MAXPIECESIZE attribute sets a maximum file size for each file in the backup set.

Control files Auto backup Format:

This tells RMAN where the controlfile backup is to be stored. The "%F" in the file name instructs RMAN to append the database identifier and backup timestamp to the backup filename. The database identifier, or DBID, is a unique integer identifier for the database.

For example, one can turn off control file auto backups by issuing:
RMAN> configure controlfile autobackup off;

Show All Command

Any of the above parameters can be changed using the commands displayed by the "show all" command.

RMAN> show all;

Mechanism of Restore and Recovery operation

RMAN> RESTORE DATABASE;

RMAN> RECOVER DATABASE;

Resynchronized Catalog

The recovery catalog should be resynchronized on a regular basis so that changes to the database structure and presence of new archive logs is recorded. Some commands perform partial and full resyncs implicitly, but if you are in doubt you can perform a full resync using the following command.

RMAN> resync catalog;

starting full resync of recovery catalog
full resync complete