# make direcory for backset file and scripts file,in my case /backup/db_bak

cd   /backup/db_bak

mkdir  scripts logs rman

#  the following is contents of  rman_backup_sh

vi  /backup/db_bak/scripts/rman_backup_sh

#!/bin/bash

# author: anbob.com

# desc: rman backup database level 0

# contact: weejar@gmail.com

export ORACLE_HOME=/oracle/product/11.2.0/db_1

export ORACLE_SID=pora40

RMAN_LOG_FILE=/backup/db_bak/logs/rman_database_backup.`date +%y%m%d%H%M`.out

# -----------------------------------------------------------------

# Initialize the log file.

# -----------------------------------------------------------------

echo>> $RMAN_LOG_FILE

chmod 666 $RMAN_LOG_FILE

echo Script $0>> $RMAN_LOG_FILE

echo ==== started on `date` ====>> $RMAN_LOG_FILE

echo>> $RMAN_LOG_FILE

ORACLE_USER=oracle

RMAN=$ORACLE_HOME/bin/rman

BACKUP_TYPE="INCREMENTAL LEVEL 0"

# ---------------------------------------------------------------------------

# Print out the value of the variables set by this script.

# ---------------------------------------------------------------------------

echo>> $RMAN_LOG_FILE

echo "RMAN: $RMAN">> $RMAN_LOG_FILE

echo "ORACLE_SID: $ORACLE_SID">> $RMAN_LOG_FILE

echo "ORACLE_USER: $ORACLE_USER">> $RMAN_LOG_FILE

echo "ORACLE_HOME: $ORACLE_HOME">> $RMAN_LOG_FILE

echo "BACKUP_TYPE: $BACKUP_TYPE">> $RMAN_LOG_FILE

# ---------------------------------------------------------------------------

echo >> $RMAN_LOG_FILE

exec 1>> $RMAN_LOG_FILE 2>&1

$RMAN target / nocatalog  <<-EOF

RUN {

 ALLOCATE CHANNEL ch00 TYPE disk;

 ALLOCATE CHANNEL ch01 TYPE disk;

 BACKUP $BACKUP_TYPE SKIP INACCESSIBLE

 TAG hot_db_bk_level0

 FORMAT '/backup/db_bak/rman/pora40_db_lv0_%T_%s_bak'

 DATABASE;

 RELEASE CHANNEL ch00;

 RELEASE CHANNEL ch01;

 ALLOCATE CHANNEL ch00 TYPE disk;

 ALLOCATE CHANNEL ch01 TYPE disk;

 BACKUP

 SKIP INACCESSIBLE

 FORMAT '/backup/db_bak/rman/pora40_arh_lv0_%T_%s_bak'

 ARCHIVELOG ALL DELETE INPUT;

 RELEASE CHANNEL ch00;

 RELEASE CHANNEL ch01;

 BACKUP

 CURRENT CONTROLFILE

 FORMAT '/backup/db_bak/rman/pora40_ctrl_%T_%s_bak';

 crosscheck backup;

 report obsolete;

 delete noprompt force obsolete;

 } 

EOF

echo "****ATTN: Database backup is finished.  The time is `date`.****" 

[oracle@dbserver40 scripts]$ ./rman_backup_sh

# add crontab job

[root@dbserver40 rman]# ll -rth

-rw-r----- 1 oracle oinstall 626M Jun 26 13:19 pora40_db_lv0_20130626_13_bak
-rw-r----- 1 oracle oinstall 166K Jun 26 13:19 pora40_arh_lv0_20130626_16_bak
-rw-r----- 1 oracle oinstall 9.4M Jun 26 13:19 pora40_ctrl_20130626_18_bak