Backup Using Rman

What is Rman?
Recovery Manager is a tool that manages the process of creating backup and also
Manages the process of restoring and recovering
The recovery catalog can also hold RMAN stored Scripts, sequences for common backup tasks. Centralized storage of scripts in recovery catalog can be more convenient than working with command files

Why use Rman ?
§ RMAN is an intelligent tool
§ Maintains repository of backup metadata.
§ Remembers backup locations
§ Knows what needs backup set locations
§ Knows what needs to be backed up
§ Knows what is required for recovery
§ Know what backups are redundant
§ It handles database corruptions
§ Parallel operation are supported
§ Better Querying facility for knowing different details of backup.
§ No Extra redo generated when backup is taken. Compared to online backup
§ Proper Security
§ It contains details of backup taken in the central repository

The Rman Architecture
RMAN This could be present and fired even from client side
Target This is the database which needs to be backed up
Auxiliary This is the database which needs to duplicate
Catalog Catalog is optional otherwise backup details are stored in target database control file.

It is a repository of information queried and updated by Recovery Manager
It is a schema or user stored in Recovery Manager
One schema can support many databases
It contains information on Physical schema of Target Database data file and archive log,

backup sets and pieces
Recovery Catalog is must in following scenarios
- In order to store scripts For Table space Point in time recovery

Media Management Software
Media management software is must if you are using RMAN for storing backup in Tape drive directly
Image copy

The advantage of image copy is it is not in RMAN proprietary format
Backup Format
RMAN backup is not in oracle format but in RMAN proprietary format.
Oracle backup comprises of backup sets and consists of backup pieces
Backup sets are logical entity
In Oracle 9i it gets stored in default locations ($ORACLE_HOME/dbs)
There are two types of backup sets

§ Datafile backup sets

§ Archivelog Backup sets
One more important point of data file backup sets is it do not include empty blocks,
A backup set will contain many backup pieces
A single backup piece consists of physical files which are in RMAN proprietary format.

Types Backups in Rman
§ Complete backup
§ Incremental backup
§ Image Copy (not in Rman nature)
These backup are of RMAN proprietary nature
Connecting Rman
1. OS authentication
2. Password File authentication

1. OS authentication
] export ORACLE_SID=targetdb
] Rman catalog mark/mike@catdb target /

2. Oracle Net authentication*
Way 1 ->] Rman target sys/sys@dbname catalog mark/mike@catdb
Way 2 ->] Rman
Rman] connect catalog mark/mike@catdb
Rman] connect target sys/sys@dbname
* TNS and LISTENER must be configured and password file must be அவைலப்லே

RMAN configuration parameters
CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default
CONFIGURE BACKUP OPTIMIZATION OFF; # default
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP OFF; # default
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default
CONFIGURE DEVICE TYPE DISK PARALLELISM 1; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO 'F: \ORACLE\ORA92\DATABASE\SNCFMUB.ORA';