Backup of backupset failed with RMAN-6500 skipping backup set key %s; already backed up %s time(s)

SYMPTOMS

Backup of backupset skipped with below messages :

RMAN> backup backupset from tag ‘<tag_name>’ format ‘/<path>/%U’;

Starting backup at 22-AUG-18
using channel ORA_DISK_1
using channel ORA_DISK_2
using channel ORA_DISK_3
using channel ORA_DISK_4
using channel ORA_DISK_5
using channel ORA_DISK_6
using channel ORA_DISK_7
using channel ORA_DISK_8
skipping backup set key 1362; already backed up 1 time(s)
skipping backup set key 1363; already backed up 1 time(s)

CAUSE

Initially  backup of database was taken on disk using below command :Rman> Backup as backupset tag ‘<tag_name>’ database;

Now the requirement is  to take backup of above backupset to different location on disk :

Rman> Backup backupset from tag ‘<tag_name>’ format ‘/<path>/%U’;

Backup optimization is ON ,therefore backup set was not copied because it is already backed up on the device type requested.
 

SOLUTION

Below are two options to resolve this issue :

1.) Turn off backup optimization :RMAN> CONFIGURE BACKUP OPTIMIZATION OFF;

2.)Take backup of backupset using force option which will override backup optimization :RMAN> Backup force backupset from tag ‘<tag_name>’  format ‘/<path>/%U’;