Backup and Recovery using Oracle RMAN

Overview of RMAN Functional Components

The RMAN environment consists of the utilities and databases that play a role in backing up your data. At a minimum, the environment for RMAN must include the following:

• The target database to be backed up


• The RMAN client, which interprets backup and recovery commands, directs server sessions to execute those commands, and records your backup and recovery activity in the target database control file.

Some environments will also use these optional components:

• A flash recovery area, a disk location in which the database can store and manage files related to backup and recovery


• Media management software, required for RMAN to interface with backup devices such as tape drives


• A recovery catalog database, a separate database schema used to record RMAN activity against one or more target databases

Please check the above diagram illustrates these components

New Features in Oracle Database 10g Release 2

Backup Set Encryption

Backup security is vital to the well-being of any company. Backups should only be able to be opened and read by their creators. With Oracle Database 10gR2, backup sets made to disk can now be encrypted, for the whole database or particular tablespaces, using the new CONFIGURE ENCRYPTION FOR [DATABASE TABLESPACE …] option.

Unused Block Compression

With unused block compression (enabled by default), only the currently used blocks are read and written during a full backup. This speeds up backups and reduces backup size. In previous releases, blocks that are currently unused, but had been used at some point in the past, were required to continue to be backed up. Also, blocks that have never been used are never backed up.

Dynamic Channel Allocation for RAC Environments

By configuring the PARALLELISM parameter, RMAN will dynamically allocate the specified number of channels across all active RAC nodes, to perform the backup or restore operation. RMAN utilizes Oracle Clusterware (formerly known as Cluster Ready Services) to allocate channels to the least loaded nodes, to perform the operations. In this way, the overall backup or restore workload can be distributed across the RAC nodes more efficiently.

Enterprise Manager Enhancements

Oracle Enterprise Manager, a single, integrated solution for administering and monitoring systems and applications based on the Oracle technology stack, is further enhanced for managing and monitoring backup jobs.

Database Control allows DBAs to view all backup jobs by date range and backup type (e.g. full, datafile, archive log), along with their status (e.g. "completed", "completed with warnings"), input and output sizes, and output rate. Each backup job can be further drilled down to review input files and output backup sets/image copies, their sizes, and compression ratio (if enabled).

Grid Control offers several enhancements to manage backups across the enterprise. Backup jobs can be viewed across all target databases, and a failed job can be easily restarted without having to resubmit the job again. In case a backup job fails, the DBA can be notified immediately via email. In addition, user-defined RMAN scripts can be created as jobs and applied to any number of target databases. The recovery wizard has also been enhanced to allow restore and recovery to a different Oracle home, in the event that the original Oracle home or database is lost.

Please find the Oracle Recovery Manager 10g overview in below PDF:
http://www.oracle.com/technology/deploy/availability/pdf/TWP_HA_RMANOverview_10g_111503.pdf

Oracle Recovery Manager 10g New Features Overview:
http://www.oracle.com/technology/deploy/availability/pdf/rman_10g_fov.pdf

Using Recovery Manager with Oracle Data Guard in Oracle Database 10g:
http://www.oracle.com/technology/deploy/availability/pdf/RMAN_DataGuard_10g_wp.pdf

RMAN Backup and Recovery Optimization:
http://www.oracle.com/technology/deploy/availability/pdf/br_optimization.pdf

RMAN and Media Manager Troubleshooting Guide:
http://www.oracle.com/technology/deploy/availability/pdf/rman_mm_troubleshoot.pdf

Oracle Database 10g Migration to Automatic Storage Management:
http://www.oracle.com/technology/deploy/availability/pdf/Technical_WP_ASM_Migration.pdf