Full backup with archivelogs

Question

I tried to do an incremental level 0 backup with archivelogs, it failed with the error messages said that can not recognize file C:\ARCHIVE\ORCL\4_1_684433700.ARC, the error code was ORA-19625. So I added "crosscheck archivelog all;" to the backup script and Redo it.
This time it succeeded, but there is still something I'm confused. I set up two folders to store the archivelogs, during the process, the archivelogs in the folders were not deleted synchronously,for example arhivelog a was deleted from one folder while the same file in the other folder was remained. Below is my backup script
RUN {
ALLOCATE CHANNEL ch00 TYPE DISK;
ALLOCATE CHANNEL ch01 TYPE DISK;
BACKUP
          incremental level 0
SKIP INACCESSIBLE
TAG hot_db_bk_level0
FILESPERSET 5
# recommended format
FORMAT '\\dell090121\rman_hotbackup\bk_full_%s_%p_%t'
DATABASE;
sql 'alter system archive log current';
RELEASE CHANNEL ch00;
RELEASE CHANNEL ch01;
# backup all archive logs
ALLOCATE CHANNEL ch00 TYPE DISK;
ALLOCATE CHANNEL ch01 TYPE DISK;
BACKUP
filesperset 20
FORMAT '\\dell090121\rman_hotbackup\al_%s_%p_%t'
ARCHIVELOG ALL DELETE INPUT;
RELEASE CHANNEL ch00;
RELEASE CHANNEL ch01;
# Note: During the process of backing up the database, RMAN also backs up the
# control file. This version of the control file does not contain the
# information about the current backup because "nocatalog" has been specified.
# To include the information about the current backup, the control file should
# be backed up as the last step of the RMAN section. This step would not be
# necessary if we were using a recovery catalog.
ALLOCATE CHANNEL ch00 TYPE DISK;
BACKUP
# recommended format
FORMAT '\\dell090121\rman_hotbackup\cntrl_%s_%p_%t'
CURRENT CONTROLFILE;
RELEASE CHANNEL ch00;
}

Answer 1

Even if you have two (or more) archivelog destination directories, the "DELETE INPUT" clause in "BACKUP ARCHIVELOG ..." would delete only archivelogs which it reads for the backup. Thus, because the backup could read from dest_1 (for instance), it would archivelogs from dest_1 but not from dest_2. The Backup is free to backup files at either dest location and delete only what it has backed up, by default with "DELETE INPUT".
However if you specify DELETE ALL INPUT, then Oracle deletes all copies of the ArchiveLogs.
Thus your backup command would be
BACKUP ARCHIVELOG ALL DELETE ALL INPUT;where the first "ALL" is "all archived log sequences available, but only 1 copy of each" while the second "ALL" is "all copies of each archived log backed up by the BACKUP"