RMAN backup to disk

[vidarka]

I have an database - size 120Gb. I have 4 servers in an Oracle9i RAC. (9.2.0.5). I want to do the RMAN-backup from node1. I have 4 dump areas - size 50Gb each. I mount 3 of them on node 1. Then I have 150Gb of dump-areas available on node1(/mnt1 + /mnt2 + /mnt3).
How do you allocate these disks in the RMAN-script so that the rman-files are placed on the 3 disks (not parallell). I want to spread the backup-files on 3 dump-areas.

 

[Matsul]

If you use the CONFIGURE command to set the MAXSETSIZE to 50G you might achive this. It specifies the maximum size for a backup set that a channel can produce

 

[karluk]

You should set the degree of parallelism to three and allocate three channels, each one pointing to one of your three dump areas. Something like

CONFIGURE DEVICE TYPE DISK PARALLELISM 3 BACKUP TYPE TO BACKUPSET;
CONFIGURE CHANNEL 1 DEVICE TYPE DISK CONNECT 'sys/pwd@instance1' FORMAT '/dump_area_1/%d/%d_%U.bak';
CONFIGURE CHANNEL 2 DEVICE TYPE DISK CONNECT 'sys/pwd@instance1' FORMAT '/dump_area_2/%d/%d_%U.bak';
CONFIGURE CHANNEL 3 DEVICE TYPE DISK CONNECT 'sys/pwd@instance1' FORMAT '/dump_area_2/%d/%d_%U.bak';

Each channel will do about a third of the work, thus spreading your backup set relatively evenly across all three dump areas.