Rac Database Backup Configuration - 11gr2

Configuring backup purely depends on the nodes where backup appliance has been configured. Here are som of the common methods followed in most of the organisations.

1. Single or muliple backup/storage media configured in first ( one ) node only.So want to run the backup from the first node only.

    This is the most common approach.Depends on the no of tape device configured,no of channels can be allocated to parallelise the rman backup. ( IT is a myth that more channels will always improve the performance of rman backup)

The below example script will help us to schedule a backup with two channels 

run {
    allocate channel t1 type 'sbt_tape'  format 'df.%d.%f.dbf_t%t_s%s_p%p.rmn'   maxpiecesize 5G  parms 'ENV=(NSR_SERVER=tape_srv)';
   allocate channel t2 type 'sbt_tape'  format 'df.%d.%f.dbf_t%t_s%s_p%p.rmn'    maxpiecesize 5G  parms 'ENV=(NSR_SERVER=tape_srv)';
  backup   incremental level 0   filesperset 10   tag 'INC1_DATABASE'    database;
 }

2. Backup/Storage media configured in all nodes and want to run the backup from all instances 

2.1 Dedicate the channel to a particular instance irrespective of the load on the instance

CONFIGURE DEFAULT DEVICE TYPE TO SBT;
CONFIGURE DEVICE TYPE SBT Parallelism 3;
configure channel 1 device type sbtconnect='rman_id/rman_pwd@racdb1';
configure channel 2 device type sbtconnect='rman_id/rman_pwd@racdb2';
configure channel 3 device type sbtconnect='rman_id/rman_pwd@racdb3';
run{
backup
     incremental level 0
     tag 'INC1_DATABASE'
     database;
 }


2.2  To run the backup based on the load,
create a service with the preferred instances and connect the backup session through the service name. Oracle will automatically direct the channels to the instances where the loads are less

CONFIGURE DEFAULT DEVICE TYPE TO SBT;
CONFIGURE DEVICE TYPE SBT Parallelism 3;
configure channel 1 device type sbt connect='rman_id/rman_pwd@Service1';

2.3 Non-determinstic connection - 11g new feature.
    With this oracle automatically decides the instance where the channel need to be run.    Just mention the parallelism will be sufficient to avail this feature.

CONFIGURE DEFAULT DEVICE TYPE TO SBT;
CONFIGURE DEVICE TYPE SBT Parallelism 3;

3.Backup/Storage media configured in Standby database

Some companies want to schedule backup from the standby database to reduce the load in the production environment. Infact standby serve this purpose without any additional effort.

Backup of standby database is similar to production, it is exactly same as production. To take consistent backup we need to cancel the recovery mode and bring the database in mount mode, otherwise the backup will be in inconsistent mode.