Daemon cron not work - linux

I am trying to use the deamon cron to add a command but didn't work.
I open the file /etc/crontab and I add the following sentence:
30 16 * * 1 root poweroff
But my system doesn't close. Please help me, I don't kow what I am doing bad.

Please, I would try the following...
sudo -i
crontab -e
Add the next line
30 16 * * 1 /sbin/poweroff
poweroff

Related

How to make linux to reboot every day?

I tried to use cron but I don't see it reboots - no one program restarts.
I wrote to my crontab -e
48 8 * * * sudo reboot
I tried to make it reboot every day at 8:48. Why it doesn't work?
Sudo? Try without sudo in root crontab.
Use sudo crontab -e and include "/sbin/" on your command "reboot.
48 8 * * * /sbin/reboot

Crontab does not run on CentOS 7

I'm using CentOS 7, and installed "cronie"
yum install cronie
I have a shell to backup my home folder, shell's content (of course, backup.sh is 775)
#!/bin/bash
#START
TIME=`date +%Y-%m-%d_%Hh%M`
FILENAME=backupHome_123.30.150.29_$TIME.tar.gz
SRCDIR=/home
DESDIR=/backup
tar -cpvzf $DESDIR/$FILENAME $SRCDIR
#END
And add to crontab -e
00 2 * * * /bin/bash /backup/backup.sh
But crontab does nothing. When I check log at /var/log/cron only, something like that and no more error or processing log
May 1 00:26:08 app crontab[12041]: (root) END EDIT (root)
May 1 00:33:21 app crontab[12086]: (root) BEGIN EDIT (root)
May 1 00:34:25 app crontab[12086]: (root) END EDIT (root)
Anyone can give me some advises to make crontab work?
Thank you.
I found that the most useful information was actually given by
systemctl status crond
Which revealed that it failed to load correctly due to an "Unauthorized SELinux context" error.
This can happen if cron daemon isn't running.
Check it with:
pgrep cron
If command returns nothing, run:
systemctl restart crond
This should help.
You want to make sure cron is started & that it is started if your server reboots so you need two commands on CentOS 7 to make sure of this:
systemctl enable crond && systemctl restart crond
If you are used to using sudo, you can add sudo in front of above command. like this:
sudo systemctl enable crond && systemctl restart crond
YOU WILL get confirmation from system, something like:
Created symlink from /etc/systemd/system/multi-user.target.wants/crond.service to /usr/lib/systemd/system/crond.service.
Then lastly check cron is running
pgrep cron
I know that I'm late to answer you, but maybe someone will have this kind of problem. It is possible that CRON can't run the script because the path is not correct.
Your path is
00 2 * * * /bin/bash /backup/backup.sh
I guess that path should be:
00 2 * * * sh /bin/bash/backup/backup.sh
Only difference is space after bash directory and sh command at the start of CRON job.
You have to add username before your command like this for example :
1 * * * * root or username /usr/bin/php /var/www/html/yourwebsite/yourscript.php

Why my scheduled job is not working?

I define a job with crontab like this
0 2 * * * dbadmin . /home/dbadmin/back.sh
it is not root I want to run this .sh file with dbadmin user.
but when I checked it is not working.
in the log it gives this:
Feb 22 21:16:01 localhost crond[14634]: (*system*) BAD FILE MODE (/etc/crontab)
Feb 22 21:16:01 localhost crond[14634]: (dbadmin) RELOAD (cron/dbadmin)
Feb 22 21:16:01 localhost crond[28451]: (dbadmin) CMD (dbadmin . /home/dbadmin/back.sh)
How can I fix this? thanks in advance
Make a crontab entry as dbadmin without the username in it:
0 2 * * * /home/dbadmin/movefolder.sh > /home/dbadmin/cron.out 2>#1
Each day the logfile /home/dbadmin/cron.out should be replaced by a new one.
When you are confident about the cron+movefolder, replace the outputfile with /dev/null.
When above fails, check calling the script as dbadmin:
sh /home/dbadmin/movefolder.sh
When this one works and cron fails, it might be the environment. Try saomething like
0 2 * * * . /home/dbadmin/.profile; /home/dbadmin/movefolder.sh > /home/dbadmin/cron.out 2>#1
Using the crontab program, you normally have access only to the 5 scheduling fields (minute, hour, day of month, month and day of week). However, with Vixie cron (usually on Linux) by editing the system crontab file (/etc/crontab, as well as files in /etc/cron.d) you can use the 6th field for the username. For example, see How to specify in crontab by what user to run script?
If you use crontab to enter this line
0 2 * * * dbadmin . /home/dbadmin/back.sh
^^^^^^^
the "dbadmin" username is treated as the command to execute. You can (as noted in crontab's manual page) use that line in /etc/crontab. I pointed out that this is Vixie (also known as ISC) crontab. Legacy systems such as Solaris have a less capable crontab which would not allow specifying the user to run under.
According to cron's manual page, it will send output via email. Perhaps there was no email because the command "dbadmin" failed.
You need to use sh command for executing sh file.like following
0 2 * * * dbadmin sh /home/dbadmin/movefolder.sh
Hope it works.
Thank you.

crontab being saved in tmp/ in debian

I'm trying to make a crontab with crontab -e, but it saves it in tmp/crontab.FTt6nI/crontab
the crons don't work so I guess that's the problem. But I don't understand why.
type:
crontab -l
to show list of crontab, your newly added crontab should be on the list. you could set the crontab to email the output to you by > youremail#aaa.com, in this way you can assure the cronjob is already run.
example:
* * * * * /usr/bin/php /home/username/public_html/cron.php > aaa#aaa.com
make sure the crond is running:
/etc/init.d/crond status
if it down, start it (centos/rhel):
/etc/init.d/crond start
debian/ubuntu:
/etc/init.d/cron start
hope that help.

Using Cron to Reboot

I'm using a Raspberry Pi for a status display, but for whatever reason it gets incredabbly sluggish after a day or so of running so I wanted to reboot it every day so I setup a cron job to do that every morning at 8:50. But, it doesn't seem to be working. Is there anything special about using cron to do a reboot?
This is my crontab for the root user:
# m h dom mon dow command
50 8 * * * shutdown now -r >> /var/log/cron.log
0,30 * * * * date >> /var/log/cron.log
The second line works just fine, but I can't seem to get the restart command to work. It doesn't even output anything to the log.
Try using the fully specified path to shutdown. date may be in the PATH in roots cron environment, /sbin may not be looked up.
You need to edit the root user crontab
sudo crontab -e
then..
50 8 * * * reboot
Save and exit.

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