Linux Start Restart and Stop The Cron or Crond Service

H
ow do I start, restart and stop the cron service under Linux / UNIX / BSD like operating systems?

Cron (crond) daemon or service
is use to execute scheduled commands or scripts. cron wakes up every
minute, examining all stored crontabs, checking each command to see if
it should be run in the current minute.

If you are using Redhat (RHEL)/Fedora Core/Cent OS


Linux use the following commands.

Task: Start cron service

To start the cron service, use:
# /etc/init.d/crond start

Task: Stop cron service

To stop the cron service, use:
# /etc/init.d/crond stop

Task: Restart cron service

To restart the cron service, use:
# /etc/init.d/crond restart

If you are using Debian or Ubuntu


Linux the following commands.

Task: Debian Start cron service

To start the cron service, use:
# /etc/init.d/cron start

OR
$ sudo /etc/init.d/cron start

Task: Debian Stop cron service

To stop the cron service, use:
# /etc/init.d/cron stop

OR
$ sudo /etc/init.d/cron stop

Task: Debian Restart cron service

To restart the cron service, use:
# /etc/init.d/cron restart

OR
$ sudo /etc/init.d/cron restart

Task : Start the cron service at boot time

It is recommended that you start the service at boot time so that job can run w/o problems.

If you are using Redhat (RHEL)/Fedora Core/Cent OS Linux use the
following commands to ensure that the service remains enabled after a
reboot:
# chkconfig crond on

You can use a text based GUI tool called ntsysv to enable crond service:
# ntsysv

If you are using Debian or Ubuntu Linux
use the following commands to ensure that the service remains enabled after
a reboot:
# rcconf

OR
$ sudo rcconf

You can use command line tool update-rc.d
:
# update-rc.d cron defaults

OR
$ sudo update-rc.d cron defaults

轉自：http://www.cyberciti.biz/faq/howto-linux-unix-start-restart-cron/