Cron jobs in Linux and its variants such as FreeBSD or CentOS which is commonly used on web hosts due to popularity of cPanel web server control panel system, is important time based scheduled tasks and commands that perform various functions such as log rotation, updates checking, system maintenance, file system cleaning, backup, service restart and etc.
Cron jobs are managed by a daemon named crond. When cron schedules are added, deleted or modified by crontab, any changes are enacted by the crond daemon. Crond daemon runs constantly in the background and checks once a minute to see if any of the scheduled jobs need to be executed. If any, crond will execute the commands. If crond process is not running, no cron jobs will be executed.
Thus, it’s important to ensure that crond daemon is running and not hanged in the system. To manage crond daemon in Linux, we can make use of “service” command.
To check the status of crond daemon:
service crond status
To stop and terminate crond process:
service crond stop
To start and run crond daemon:
service crond start
To restart crond service:
service crond restart