How do I start, restart and stop the cron service under a Linux / BSD / UNIX-like operating systems using command prompt?

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.

Commands for RHEL/Fedora/CentOS/Scientific Linux user

If you are using Redhat (RHEL)/Fedora/CentOS Linux use the following commands.

Task: Start cron service

To start the cron service, use:
# /etc/init.d/crond start
OR RHEL/CentOS 5.x/6.x user:
# service crond start
OR RHEL/Centos Linux 7.x user:
# systemctl start crond.service

Task: Stop cron service

To stop the cron service, use:
# /etc/init.d/crond stop
OR RHEL/CentOS 5.x/6.x user:
# service crond stop
OR RHEL/Centos Linux 7.x user:
# systemctl stop crond.service

Task: Restart cron service

To restart the cron service, use:
# /etc/init.d/crond restart
OR RHEL/CentOS 5.x/6.x user:
# service crond restart
OR RHEL/Centos Linux 7.x user:

# systemctl restart crond.service

Commands for Ubuntu/Mint/Debian based Linux distro

If you are using Debian or Ubuntu or Mint 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
OR
$ sudo service 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
OR
$ sudo service 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
OR
$ sudo service 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