ora-20242/rman-20242

[root@newadm ~]# more /home1/oracle/backup/sh/rman_backup.sh 
. $HOME/.bash_profile
export workdate=`date +"%Y%m%d"`
export begindate=`date +"%Y%m%d-%T"`


rman target  /<<  END
run{
  ALLOCATE CHANNEL dev1 DEVICE TYPE DISK FORMAT '/home1/oracle/backup/data/hot/backup/full_%d_%T_%u.back';
  CONFIGURE CONTROLFILE AUTOBACKUP ON; 
  CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '/home1/oracle/backup/data/hot/backup/%F'; 
  BACKUP  AS COMPRESSED BACKUPSET DATABASE plus archivelog;
  DELETE NOPROMPT ARCHIVELOG until time 'sysdate - 7';
  release CHANNEL dev1;
}
crosscheck backup;
delete noprompt obsolete;
exit
END


cp /home1/oracle/backup/data/hot/backup/*`date +%Y%m%d`*  /home1/oracle/backup/data/hot/backup_bak
rm -f /home1/oracle/backup/data/hot/backup_bak/*_MAILDATA_`date "+%Y%m%d" -d'-2 days'`_*.back




begin_line=`cat -n  /home1/oracle/backup/sh/rman_backup.log|grep "connected to target database"|awk '{print $1}'|tail -1`
sed  -n ''$begin_line',$p' /home1/oracle/backup/sh/rman_backup.log |grep -i ora- >/home1/oracle/backup/sh/rman_backup.lst


export myfile=/home1/oracle/backup/sh/rman_backup.lst
export filsiz=`ls -al $myfile | awk '{print $5}'`
export file=0
export enddate=`date +"%Y%m%d-%T"`
    
    if [ "$filsiz" = "$file" ]; then
        echo......
    else
        echo ......
    fi

else
今天在使用以上rman脚本备份的时候报错ora-20242,因为这个脚本在别的机器上测试过没有问题的，为甚在这个就报错那？？？
唯一有问题的地方就是DELETE NOPROMPT ARCHIVELOG until time 'sysdate - 7';
原来：如果使用sysdate-7的话，那么7天以内的规定那个必须存在不然就会报这个错误，看来还是对rman不熟悉啊...