各位大侠，大家好！

我的生产库是http://www.itpub.net/tree/index_1/]oracle10.2.0.4版本，rac集群。
操作系统是redhat5.5 64位的。
最近生产库备份的时候，我的rman备份策略是
[oracle@oracle1 rmanbak]$ rman
Recovery Manager: Release 10.2.0.4.0 - Production on Wed Mar 19 10:35:35 2014
Copyright (c) 1982, 2007, Oracle. All rights reserved.
RMAN> connect target /
connected to target database: PROD (DBID=244707253)
RMAN> show all;
using target database control file instead of recovery catalog
RMAN configuration parameters are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 7;
CONFIGURE BACKUP OPTIMIZATION OFF;
CONFIGURE DEFAULT DEVICE TYPE TO DISK;
CONFIGURE CONTROLFILE AUTOBACKUP OFF;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F';
CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET;
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1;
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1;
CONFIGURE MAXSETSIZE TO UNLIMITED;
CONFIGURE ENCRYPTION FOR DATABASE OFF;
CONFIGURE ENCRYPTION ALGORITHM 'AES128';
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE;
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/u01/oracle/product/10.2.0/db_1/dbs/snapcf_prod1.f';
但是每次备份完删除过期日志的时候，都不能把数据文件备份集，全部删除。只删除了一部分，
rman备份的log中也没有报错信息。这个是什么缘故，请大侠们给指点迷津，在下感激不敬！