When you try to schedule backups under corntab as Oracle user, you might encounter crontab permission error
[oracle@plcdbprod ~]$ crontab -l cron/oracle: Permission denied
The error is because of permission issues on /usr/bin/crontab le. Login as root user and find the crontab permissions on /usr/bin/crontab
[root@plcdbprod ~]# ls -l /usr/bin/crontab -rwxr-xr-x 1 root root 315432 Jul 15 2008 /usr/bin/crontab
Give the below permissions to /usr/bin/crontab file
[root@plcdbprod ~]# chmod 4755 /usr/bin/crontab [root@plcdbprod ~]# ls -l /usr/bin/crontab -rwsr-xr-x 1 root root 315432 Jul 15 2008 /usr/bin/crontab
Login as oracle user and check your crontab -e.