RMAN-06808: SECTION SIZE cannot be used when piece limit is in effect

1.Backup fails with RMAN-06808 errorm message

RMAN> backup
2> as backupset
3> datafile 2
4> section size=250m
5> ;

Starting backup at 12-jun-2014 12:44:49
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=51 device type=DISK
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of backup command at 06/12/2014 12:44:50
RMAN-06808: SECTION SIZE cannot be used when piece limit is in effect

2.Cleared the persistent channel configuration, but still the error exist

RMAN> show channel
2> ;

RMAN configuration parameters for database with db_unique_name CVRMAN are:
CONFIGURE CHANNEL DEVICE TYPE DISK RATE 100 M;

RMAN> show all;

RMAN configuration parameters for database with db_unique_name CVRMAN are:
CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 7 DAYS;
CONFIGURE BACKUP OPTIMIZATION ON;
CONFIGURE DEFAULT DEVICE TYPE TO DISK;
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '+DATA/%F';
CONFIGURE DEVICE TYPE DISK BACKUP TYPE TO COMPRESSED BACKUPSET PARALLELISM 1;
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1;
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1;
CONFIGURE CHANNEL DEVICE TYPE DISK RATE 100 M;
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;
CONFIGURE EXCLUDE FOR TABLESPACE 'EXAMPLE';
CONFIGURE AUXNAME FOR DATAFILE '+DATA/cvrman/datafile/system.304.849559339' TO '+DATA/crman/datafile/system.431.849623989';
CONFIGURE AUXNAME FOR DATAFILE '+DATA/cvrman/datafile/sysaux.286.849559341' TO '+DATA/crman/datafile/sysaux.432.849623989';
CONFIGURE AUXNAME FOR DATAFILE '+DATA/cvrman/datafile/undotbs1.270.849559341' TO '+DATA/crman/datafile/undotbs1.442.849623989';
CONFIGURE AUXNAME FOR DATAFILE '+DATA/cvrman/datafile/users.391.849559341' TO '+DATA/crman/datafile/users.441.849623991';
CONFIGURE AUXNAME FOR DATAFILE '+DATA/cvrman/datafile/example.dbf' TO '+DATA/crman/datafile/example.443.849623989';
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '+DATA/snapcf2_cvrman.f';

RMAN> configure channel device type disk clear;

old RMAN configuration parameters:
CONFIGURE CHANNEL DEVICE TYPE DISK RATE 100 M;
old RMAN configuration parameters are successfully deleted
released channel: ORA_DISK_1
starting full resync of recovery catalog
full resync complete

RMAN> backup
2> as backupset
3> datafile 2
4> section size=200m
5> tag="bkp_section_df2";

Starting backup at 12-jun-2014 12:49:18
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=51 device type=DISK
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of backup command at 06/12/2014 12:49:19
RMAN-06808: SECTION SIZE cannot be used when piece limit is in effect

3.Just disconnected the RMAN session and reconnected again backup operation is working fine, may be resync catalog also works,but not tried at that time.

RMAN> show channel;

RMAN configuration parameters for database with db_unique_name CVRMAN are:
RMAN configuration has no stored or default parameters

RMAN>

RMAN>

RMAN> exit


Recovery Manager complete.
[oracle@ol6-112-rac1 ~]$ rman target="/" catalog="rman/rman@orcl1"

Recovery Manager: Release 11.2.0.3.0 - Production on Thu Jun 12 12:51:03 2014

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

connected to target database: CVRMAN (DBID=659771233)
connected to recovery catalog database

RMAN> backup
2> as backupset
3> datafile 2
4> section size=200m
5> tag="bkp_section_df2";

Starting backup at 12-jun-2014 12:51:32
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=27 device type=DISK
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=+DATA/cvrman/datafile/sysaux.286.849559341
backing up blocks 1 through 25600
channel ORA_DISK_1: starting piece 1 at 12-jun-2014 12:51:38