[oracle@o71 ~]$ rman target /

Recovery Manager: Release 18.0.0.0.0 - Production on Thu Jan 10 23:13:57 2019
Version 18.4.0.0.0

Copyright (c) 1982, 2018, Oracle and/or its affiliates.  All rights reserved.

connected to target database (not started)

RMAN> startup mount

Oracle instance started
database mounted

Total System Global Area     536867640 bytes

Fixed Size                     8659768 bytes
Variable Size                327155712 bytes
Database Buffers             192937984 bytes
Redo Buffers                   8114176 bytes

RMAN> show all;

RMAN configuration parameters for database with db_unique_name MIN18 are:
CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 7 DAYS;
CONFIGURE BACKUP OPTIMIZATION ON;
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP ON; # default
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '/oracle_backup/MIN18/%F';
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   '/oracle_backup/MIN18/%U';
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE ENCRYPTION FOR DATABASE OFF; # default
CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default
CONFIGURE COMPRESSION ALGORITHM 'BASIC' AS OF RELEASE 'DEFAULT' OPTIMIZE FOR LOAD TRUE ; # default
CONFIGURE RMAN OUTPUT TO KEEP FOR 7 DAYS; # default
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/u01/app/oracle/product/18.0.0/dbhome_1/dbs/snapcf_MIN18.f'; # default

RMAN> backup full database;

Starting backup at 10-JAN-19
using channel ORA_DISK_1
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00002 name=/oradata/MIN18/data_D-MIN18_I-2460040847_TS-SYSAUX_FNO-2_03tmvlae
input datafile file number=00001 name=/oradata/MIN18/data_D-MIN18_I-2460040847_TS-SYSTEM_FNO-1_04tmvlah
input datafile file number=00003 name=/oradata/MIN18/data_D-MIN18_I-2460040847_TS-UNDOTBS1_FNO-3_05tmvlai
input datafile file number=00004 name=/oradata/MIN18/data_D-MIN18_I-2460040847_TS-USERS_FNO-4_06tmvlaj
channel ORA_DISK_1: starting piece 1 at 10-JAN-19
channel ORA_DISK_1: finished piece 1 at 10-JAN-19
piece handle=/oracle_backup/MIN18/0ktn0tuv_1_1 tag=TAG20190110T232102 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:15
Finished backup at 10-JAN-19

Starting Control File and SPFILE Autobackup at 10-JAN-19
piece handle=/oracle_backup/MIN18/c-2460040847-20190110-07 comment=NONE
Finished Control File and SPFILE Autobackup at 10-JAN-19

RMAN> backup full database;

Starting backup at 10-JAN-19
using channel ORA_DISK_1
skipping datafile 1; already backed up 1 time(s)
skipping datafile 2; already backed up 1 time(s)
skipping datafile 3; already backed up 1 time(s)
skipping datafile 4; already backed up 1 time(s)
Finished backup at 10-JAN-19

RMAN>