1) PROD-DR:oracle[/backup/flash_recovery_area/PROD/backupset] du -s *
2) PROD-DR:oracle[/backup/flash_recovery_area/PRODDR/archivelog] du -s *
Are you sure there is only one database available? if you see for the backupset the sub directory is "PROD" but for archivelogs the sub direcotry is "PRDODR". you might looking at two different paths?
First examine server how many databases resides, connect to instance and check where the archives are lcoated physically and so on.
Yeah there is just one, So It the PROD folder might me an ftp of the primary db rman backup?
That you will know better because you have access to your envrionement
Simply you can check RMAN backup status and then check size from primary and then verify to standby.. HTH.
So this is just to confirm that at standby db server, only archivelogs are generated and no backupset right?
The purpose of these backupset is just to recreate the standby in case it gets corrupted or crashed or unusable for some reason.
Of course archives will be generated, but regarding the backup sets you have to compare primary and standby as i mentioned earlier.
yes, to ensure backup copied to another server for safety reasons.. Still you need to confirm whether the backups are belongs to primary or not.. Then you can confirm