How to find which files need to be backup?

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REPORT Commands :
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Report commands list/report specific information.


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How to find which files need to backup?
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 rman

Recovery Manager: Release 11.2.0.1.0 - Production on Fri Dec 27 22:07:16 2013

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RMAN> connect target /;

connected to target database: PROD (DBID=246965557)
RMAN> report need backup;

RMAN retention policy will be applied to the command
RMAN retention policy is set to redundancy 2
Report of files with less than 2 redundant backups
File #bkps Name
---- ----- -----------------------------------------------------
2    0     /d01/oracle/oradata/prod/sysaux01.dbf
3    0     /d01/oracle/oradata/prod/undotbs01.dbf
4    0     /d01/oracle/oradata/prod/users01.dbf