HOWTO: Schedule jobs with cron on OpenWrt

No additional software needs to be installed on OpenWrt, as it already has the crond binary included.

Configuration

Cron jobs need to be specified in /etc/crontabs/root. For now, just create an empty file:

# touch /etc/crontabs/root

Create a symbolic link to the crontab file:

# ln -sf /etc/crontabs/root /etc/crontab

it allows me to reference the crontab file using /etc/crontab.

Enable and start crond:

# /etc/init.d/crond start
# /etc/init.d/crond enable

Verify that crond successfully started by checking the syslog using:

# logread

and you should see something similar to this at the end of the logread output

Sep 11 17:26:40 OpenWrt cron.info crond[634]: crond: crond (busybox 1.19.4) started, log level 8

Usage

Now that you have crond running on OpenWrt, it can be used to periodically run any task that you want. Just add an entry to/etc/crontab for each task that you want periodically executed.

For example, if you want to run a script (/usr/bin/demo) daily at 23:30, the following would be added to crontab:

30 23 * * * /usr/bin/demo >/dev/null 2>&1

Restart crond to make this change take effect:

# /etc/init.d/cron restart