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22 Setting Up the Dell™ DR Series System as an NFS or CIFS Backup Target on Oracle Recovery Manager® |
April 2015
7 General best practices for RMAN backups to the DR Series
system
The Dell DR Series system supports RMAN backups over both CIFS and NFS protocols. With client side
optimization drivers like Rapid CIFS and Rapid NFS backups become faster and more efficient. Several
options exist with RMAN that every DBA should be aware of. These effect how RMAN behaves when
performing its backup duties. Some of the most important are outlined here because they affect how
RMAN will interact with a Dell DR Series deduplication appliance. Refer to Oracle’s documentation for
more details.
Multiplexing of data is not recommended as it adversely affects the deduplication savings. Every time data
gets multiplexed, the patterns may change, and the deduplication algorithm can fail to decipher the
duplicates. Specify FILESPERSET = 1 when backing up to a DR Series system. FILESPERSET controls how
many data files are written to a particular file within the backup set.
 Backup database FILESPERSET=1
Specify MAXOPENFILES = 1 for each channel defined. This will ensure that each RMAN channel only
reads from a single file at any one time. It is recommended to keep the value at minimum.
 CONFIGURE CHANNEL DEVICE TYPE DISK MAXOPENFILES 1 FORMAT '<UNCPath of the DR
container>/ora_df%t_s%s_s%p';
 Turn on change block tracking by using below command.
SQL> ALTER DATABASE ENABLE BLOCK CHANGE TRACKING USING FILE '<Path on the RMAN server
Oracle Home>/oradata/rman_change_track.f';
 Configure RMAN settings to backup control file and SPFILE.
Auto backup on
CONFIGURE CONTROLFILE AUTOBACKUP ON;
Keep CONFIGURE BACKUP OPTIMIZATION OFF every time for better savings.
RMAN encryption should NOT be used as the deduplication savings get affected.
A listing of the global parameters can be generated by the “show all” RMAN command:
RMAN> show all;
RMAN configuration parameters for database with db_unique_name APPLE are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default
CONFIGURE BACKUP OPTIMIZATION OFF; # default
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default
CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE CHANNEL DEVICE TYPE DISK FORMAT '/mnt/apple_nfs/apple_%u_%s_%p';
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE ENCRYPTION FOR DATABASE OFF; # default
CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default