Error log:

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of backup command at 06/23/2017 09:00:03
RMAN-06059: expected archived log not found, loss of archived log compromises recoverability
ORA-19625: error identifying file /BACKUP/arch/ifsprod/1_153555_775842324.dbf
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3

RMAN backup failed with above mentioned errors, error message itself very explanatory, required archive log missing from archive log location and RMAN didn’t get it to backup. In my case, archive logs are moved to another location in order to manage bulk space for huge database activity. Fortunately, I have found out missing one, copied to the default location and backup was successful.

But, In case it was deleted or corrupted in worst, you can issue following commands in order to continue RMAN backup.

RMAN> crosscheck archivelog all;
RMAN> delete expired archivelog all;

OR

If you are using catalog database to maintain RMAN repository instead of controlfile, you can try following command:

RMAN> resync catalog;

Run backup again.

Note: One full database RMAN backup should consider, if you are taking RMAN transactactional or incremental backup.