Restarting cron after changing crontab file?

Question

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

Not to disregard @leonbloy's answer, but I found that implementing my linux's first cron job (a correctly formatted per minute job) didn't action until the system was rebooted. `sudo service cron restart` wasn't tested. — geotheory, Jul 02 '14 at 09:56
@geotheory yikes I sure hope I don't have to restart my prod server any time I update my crontab (and I don't). — jcollum, Nov 08 '16 at 20:46

score 807 · Accepted Answer · edited Aug 05 '16 at 09:44

807

No.

...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

edited Aug 05 '16 at 09:44

Ani Menon

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answered Apr 17 '12 at 15:12

leonbloy

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If using cron.d folder, symlinked crontabs will not be reloaded. How can I force a reload? – CMCDragonkai Jan 10 '14 at 18:00
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@CMCDragonkai `/etc/init.d/cron restart` ? – leonbloy Jan 10 '14 at 18:12
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Ah it's that easy. It's now `sudo service cron restart`. – CMCDragonkai Jan 10 '14 at 18:25
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Better option is reload - it can be initiated by non-root user: ```/etc/init.d/cron reload``` – Honza May 06 '14 at 04:50
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@CMCDragonkai Possibly `crond` instead of `cron`. – Cees Timmerman Jul 21 '15 at 12:48
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The only problem with this answer is that it's not always true. See geotheory's comment underneath the question. I, too, was bit by this. I made a change to the crontab file via `sudo crontab -e`, saved the change by `Ctrl + X`, and went away assuming `cron` would pick it up (due to this answer being so highly upvoted). Then, days later my client reports that the cron is still running on the old cycle. So - honestly - if you want to be safe - just restart either `cron` or the system, and don't play around with wasted time testing, which you'll have to do despite this highly-upvoted answer. – Dan Nissenbaum Oct 14 '15 at 22:53
sudo service crond reload works for me to reload de cron definition files on /etc/crontab – ChoCho Mar 28 '18 at 20:26
On FreeBSD and OpenBSD you need to restart the cron service after create a file under /var/cron/tabs/user or /var/cron/tabs/user – rfmoz Aug 15 '18 at 09:12
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On my Raspberry Pi 3+ with Ubuntu 18.04.2 LTS the only command that worked for me was: `sudo service cron reload`. It was also the only command which gave a response: `* Reloading configuration files for periodic command scheduler cron`. – Jan Apr 19 '19 at 08:44
I guess this is distribution-specific. On Ubuntu 20.04, with default (Vixie) cron, plain edits (with `vim`, not `crontab`) to a user-specific crontab (`/var/spool/cron/crontabs/user-foo`) *are* picked up and acted on immediately; tested with a per-minute echo and `tail`ing the user's mail file. This is also true if you simply copy in the user's cron file during installation. – EML Jan 30 '22 at 17:48

score 75 · Answer 2 · edited Nov 08 '16 at 20:19

75

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

On CentOS7: sudo systemctl start crond.service

edited Nov 08 '16 at 20:19

jcollum

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answered Oct 09 '14 at 11:28

Sheldmandu

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Thanks for the CentOs 7 line – Mathieu de Lorimier Dec 15 '17 at 02:50
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// , To reload `crond`, rather than just start it on the increasingly horrible systemd, run `sudo systemctl reload crond.service`. – Nathan Basanese Oct 03 '18 at 18:26
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@NathanBasanese Reloading `cron` on SystemD now is considered black magic: `sudo systemctl reload crond` fails with `Failed to reload cron.service: Job type reload is not applicable for unit cron.service.` (Ubuntu 18.04). Read: Heads off, we all are pwned by the syndrome: "SystemD, there can be only one". If reload is not done automagically behind the scenes, you are bust! Do not even think about fixing it, like you did for the last 3 (or more) decades! Read: **The world of Windows has finally swallowed Debian: If there's something strange under the hood, what you gonna do? Restart!** – Tino Jan 16 '19 at 19:55
Restart is more than just reload. Isn't there a clean reload option available for Centos? – Ωmega Apr 18 '19 at 19:46
@Tino you can install cronie – Bob Jun 19 '19 at 11:30

score 45 · Answer 3 · edited Apr 21 '17 at 01:45

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

sudo service cron restart

edited Apr 21 '17 at 01:45

Niclas

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answered Oct 01 '16 at 15:14

Gyro

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I see only `reload` is enough. No need `restart`. Thanks. :) – Tien Nguyen Jan 13 '20 at 06:43
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In my case Rasperian with PI zero and changes in /var/spool/cron/crontabs/root I had to use `restart` – mikep Aug 10 '21 at 11:30
Had the same problem as @mikep on an old openSUSE 10 machine. Only `restart` worked. – mgutt Oct 05 '21 at 08:08

score 20 · Answer 4 · answered Mar 30 '21 at 05:55

Commands for RHEL/Fedora/CentOS/Scientific Linux user

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
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
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

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
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
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/

This does not appear to attempt to answer the question at the top of this page at all. Please review the [help] and in particular [How do I write a good answer?](/help/how-to-answer) — tripleee, Mar 30 '21 at 06:02

score 17 · Answer 5 · answered Jun 10 '15 at 09:32

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.

perhaps HUPping the process works in systems with service reload disabled? — teknopaul, Feb 08 '23 at 17:13

score 12 · Answer 6 · answered Feb 13 '17 at 08:15

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try this one for centos 7 : service crond reload

answered Feb 13 '17 at 08:15

Flair

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Or `systemctl reload crond` – pooya13 Jun 19 '20 at 20:02

score 10 · Answer 7 · edited Sep 15 '22 at 07:53

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If file /var/spool/cron/crontabs/root edited via SFTP client - service cron restart needed. Reload service not work.
If edited file /var/spool/cron/crontabs/root via console linux (nano, mc) - restart NOT needed.
If edited cron via crontab -e - restart NOT needed.

edited Sep 15 '22 at 07:53

Danijel

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answered Jan 16 '20 at 19:01

vebmaster

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score 7 · Answer 8 · answered Oct 09 '14 at 18:41

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

answered Oct 09 '14 at 18:41

jono

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Doesn't work on my Raspberry Pi 3+ with Ubuntu 18.04.2 LTS – Jan Apr 19 '19 at 08:25

score 5 · Answer 9 · answered Jan 26 '19 at 12:53

5

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

answered Jan 26 '19 at 12:53

ako

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`crond` unrecognized service. It work with `cron` for me. my OS is Ubuntu 18.04 – Tien Nguyen Dec 31 '19 at 05:17

score 3 · Answer 10 · answered Nov 26 '19 at 01:56

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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

answered Nov 26 '19 at 01:56

Mawty

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score 3 · Answer 11 · answered Sep 24 '20 at 08:49

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.

score 2 · Answer 12 · answered Feb 27 '20 at 06:08

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Ubuntu 18.04 * Usage: /etc/init.d/cron {start|stop|status|restart|reload|force-reload}

answered Feb 27 '20 at 06:08

Aqua Huang

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Restarting cron after changing crontab file?

12 Answers12

Commands for RHEL/Fedora/CentOS/Scientific Linux user

Commands for Ubuntu/Mint/Debian based Linux distro

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