Restarting cron after changing crontab file?

Do I have to restart cron after changing the crontable file?

No.

From the cron man page:

> ...cron will then examine the modification time on all crontabs > and reload those which have changed. Thus cron need not be restarted > whenever a crontab file is modified

But if you just want to make sure its done anyway,

sudo service cron reload

or

/etc/init.d/cron reload

On CentOS with cPanel sudo /etc/init.d/crond reload does the trick.

On CentOS7: sudo systemctl start crond.service

I had a similar issue on 16.04 VPS Digital Ocean. If you are changing crontabs, make sure to run

sudo service cron restart 

Depending on distribution, using "cron reload" might do nothing. To paste a snippet out of init.d/cron (debian squeeze):

reload|force-reload) log_daemon_msg "Reloading configuration files for periodic command scheduler" "cron"
    # cron reloads automatically
    log_end_msg 0
    ;;

Some developer/maintainer relied on it reloading, but doesn't, and in this case there's not a way to force reload. I'm generating my crontab files as part of a deploy, and unless somehow the length of the file changes, the changes are not reloaded.

Commands for RHEL/Fedora/CentOS/Scientific Linux user

1. 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

2. 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

3. 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

1. 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

2. 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

3. 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

Source: https://www.cyberciti.biz/faq/howto-linux-unix-start-restart-cron/

try this one for centos 7 : service crond reload

Try this out: sudo cron reload It works for me on ubuntu 12.10

1. If file /var/spool/cron/crontabs/root edit via SFTP client - need service cron restart. Reload service not work.

2. If edit file /var/spool/cron/crontabs/root via console linux (nano, mc) - restart NOT need.

3. If edit cron via crontab -e - restart NOT need.

Try this: service crond restart, Hence it's crond not cron.

There are instances wherein cron needs to be restarted in order for the start up script to work. There's nothing wrong in restarting the cron.

sudo service cron restart

Ubuntu 18.04

• Usage: /etc/init.d/cron {start|stop|status|restart|reload|force-reload}

On CentOS (my version is 6.5) when editing crontab you must close the editor to reflect your changes in CRON.

crontab -e

After that command You can see that new entry appears in /var/log/cron

Sep 24 10:44:26 ***** crontab[17216]: (*****) BEGIN EDIT (*****)

But only saving crontab editor after making some changes does not work. You must leave the editor to reflect changes in cron. After exiting new entry appears in the log:

Sep 24 10:47:58 ***** crontab[17216]: (*****) END EDIT (*****)

From this point changes you made are visible to CRON.