You have created a script to perform the backup and have tested it to verify that it works as expected. However when the script is executed in CRON it either appears to not run or it runs with errors.
In many cases the problem is that the script does not EXPORT the proper environment variables. While CRON does run the script as the user who scheduled the job, it does not run execute the users .profile or .bash_profile.
In the following script we simply pull all of the environment variables that contain ORACLE.
[oracle@prod ~]$ cat crontest.sh set | grep -i oracle > cronenv.txt [oracle@prod ~]$
If we were to execute the command in a terminal session as the oracle user we would get the following output.
[oracle@prod ~]$ ./crontest.sh [oracle@prod ~]$ cat cronenv.txt GTK_RC_FILES=/etc/gtk/gtkrc:/home/oracle/.gtkrc-1.2-gnome2 HOME=/home/oracle LOGNAME=oracle MAIL=/var/spool/mail/oracle ORACLE_BASE=/u01/app ORACLE_HOME=/u01/app/oracle/product/11.2.0/dbhome_1 ORACLE_SID=proddb PATH=/u01/app/oracle/product/11.2.0/dbhome_1/bin:/usr/kerberos/bin:/usr/local/bin:/usr/bin:/bin:/usr/X11R6/bin:/home/oracle/bin PWD=/home/oracle USER=oracle USERNAME=oracle [oracle@prod ~]$
Notice that the ORACLE_* environment variables are present and the PATH includes the ORACLE_HOME/bin location. Below we set up a CRON job to run the above script every minute.
[oracle@prod ~]$ crontab -e no crontab for oracle - using an empty one */1 * * * * /home/oracle/crontest.sh crontab: installing new crontab [oracle@prod ~]$ rm cronenv.txt [oracle@prod ~]$
Looking at cronenv.txt after CRON executed the script we see the following. Notice how none of the ORACLE_* environment variables are set.
[oracle@prod ~]$ cat cronenv.txt BASH_SOURCE=([0]="/home/oracle/crontest.sh") HOME=/home/oracle LOGNAME=oracle PWD=/home/oracle USER=oracle _=/home/oracle/crontest.sh You have new mail in /var/spool/mail/oracle [oracle@prod ~]$
When scheduling scripts in CRON you must ensure the scripts sets the appropriate environment variables. Below we change the script to include the ORACLE_* environment variables and ensure that the PATH contains the ORACLE_HOME/bin.
[oracle@prod ~]$ vi crontest.sh [oracle@prod ~]$ cat crontest.sh export ORACLE_BASE=/u01/app export ORACLE_HOME=/u01/app/oracle/product/11.2.0/dbhome_1 export ORACLE_SID=proddb export PATH=$ORACLE_HOME/bin:$PATH set | grep -i oracle > /home/oracle/cronenv.txt [oracle@prod ~]$ rm cronenv.txt [oracle@prod ~]$
Now when we look at the cronenv.txt after CRON executed the script we see that all of the appropriate environment variables are set.
[oracle@prod ~]$ cat cronenv.txt BASH_SOURCE=([0]="/home/oracle/crontest.sh") HOME=/home/oracle LOGNAME=oracle ORACLE_BASE=/u01/app ORACLE_HOME=/u01/app/oracle/product/11.2.0/dbhome_1 ORACLE_SID=proddb PATH=/u01/app/oracle/product/11.2.0/dbhome_1/bin:/usr/bin:/bin PWD=/home/oracle USER=oracle [oracle@prod ~]$