How to backup all archivelog ?

[oracle@wasiq ~]$ rman

Recovery Manager: Release 11.2.0.1.0 - Production on Fri Jan 10 22:26:10 2014

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RMAN> connect target /;

connected to target database: PROD (DBID=246965557)

RMAN> backup archivelog all;

Starting backup at 10-JAN-14
current log archived
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=133 device type=DISK
skipping archived log file /d01/oracle/flash_recovery_area/PROD/archivelog/2013_12_30/o1_mf_1_14_9d33yjqw_.arc; already backed up 1 time(s)
skipping archived log file /d01/oracle/flash_recovery_area/PROD/archivelog/2014_01_01/o1_mf_1_15_9d71k9d8_.arc; already backed up 1 time(s)
skipping archived log file /d01/oracle/flash_recovery_area/PROD/archivelog/2014_01_01/o1_mf_1_16_9d743k8w_.arc; already backed up 1 time(s)
skipping archived log file /d01/oracle/flash_recovery_area/PROD/archivelog/2014_01_01/o1_mf_1_17_9d744cr5_.arc; already backed up 1 time(s)
skipping archived log file /d01/oracle/flash_recovery_area/PROD/archivelog/2014_01_01/o1_mf_1_18_9d7454yp_.arc; already backed up 1 time(s)
channel ORA_DISK_1: starting archived log backup set
channel ORA_DISK_1: specifying archived log(s) in backup set
input archived log thread=1 sequence=19 RECID=17 STAMP=836063753
input archived log thread=1 sequence=20 RECID=18 STAMP=836066791
input archived log thread=1 sequence=21 RECID=19 STAMP=836319224
input archived log thread=1 sequence=22 RECID=20 STAMP=836517626
input archived log thread=1 sequence=23 RECID=21 STAMP=836519184
channel ORA_DISK_1: starting piece 1 at 10-JAN-14
channel ORA_DISK_1: finished piece 1 at 10-JAN-14
piece handle=/d01/oracle/flash_recovery_area/PROD/backupset/2014_01_10/o1_mf_annnn_TAG20140110T222624_9f09krqr_.bkp tag=TAG20140110T222624 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:07
Finished backup at 10-JAN-14

RMAN>