RMAN

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RMAN Configuration Parameters
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Topic :  Description of few parameters in the RMAN Configuration settings


CONFIGURE RETENTION POLICY TO REDUNDANCY 1;
CONFIGURE BACKUP OPTIMIZATION OFF; CONFIGURE DEFAULT DEVICE TYPE TO DISK; CONFIGURE CONTROLFILE AUTOBACKUP OFF; CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO %Ff;
CONFIGURE DEVICE TYPE DISK PARALLELISM 1; CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1;
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1;
CONFIGURE MAXSETSIZE TO UNLIMITED; CONFIGURE SNAPSHOT CONTROLFILE;


Solution:
RMAN CONFIGURATION PARAMETERS

RMAN has several configuration parameters, which are set to their default values when you first use RMAN. Use show all command to see the default values

RMAN>show all;
By using the V$RMAN_CONFIGURATION view you can view the current configuration values of all the RMAN parameter
By using configure command we can change RMAN configuration parameters

Backup Retention Polity

A backup retention policy tells RMAN to consider backups of datafiles and log files obsolete. You can set a retention policy by using either of two methods: the default redundancy option or recovery window

The Redundancy Option

The Redundancy option lets you specify how many copies of the backups you want to retain
The default is one
You set retention policy this way

RMAN>configure retention policy to REDUNDANCY 2;

The previous RMAN command specifies the RMAN keep only two backups of each database files

The Recovery Window Option

The recovery window refers to a time frame in which all backups will be kept, regardless of how many backups are taken you can set recovery window as follows

RMAN>configure retention policy

To recovery window of 14 days
If you set your policy to a erecovery window of 14 days then all the backups less than 14days old would be retained, and all backups older than 14days would be marked for deletion

Default Device Type

The default device for backups is disk; that is RMAN will automatically backup files to file system on you server. If you want to backup to tape, you configure the default device type of sbt

RMAN>configure default device to type to sbt;
If you wish to switch the default device back to disk then
RMAN>configure default device type to disk;

Channel Configuration

An RMAN session must use some kind of a connection to the server to perform backup and recovery work, and channels represent those connection
If you have four channels configured, four connections will be made to target database to open four separate server sessions
The following example configures two channels with channel 1 backup to the backup directory under /test01 and channel 2 backing up to backup directory under /test02

RMAN>configure channel 1 device type disk format e/test01/app/oracle/oradata/backup/%Uf;

RMAN>configure channel 2 device type disk format e/test02/app/oracle/oradata/backup/%Uf;

Degree of Parallelism

When two or more channels are allocated for single backup operation this is reffered to parallelization. The degree of parallelism denotes the number of channels that RMAN open during a backup or recovery. The time taken to complete the backup or recovery will decrease as you increase degree of parallelism

RMAN>configure device type disk parallelism4;

Backup optimization

The backup optimization option ensure that RMAN doesnft perform a file backup if it has already backed up identical versions of the file
RMAN>configure backup optimization ON;

Control File Auto backup