Cron is a time-based job scheduler in Unix-like computer operating systems. Cron enables users to schedule jobs (commands or shell scripts) to run periodically at certain times or dates.

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Cron job execution time

I added a job for backup to my cron jobs, using crontab -e: 0 0 * * * tar -czf /somewhere/backup.tar.gz --exclude='sth/backup' --directory='/var/www' sth But when I check the created file, with ...
24
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3answers
11k views

What does * * * * * (five asterisks) in a cron file mean? [duplicate]

The first noncomment line in a legacy crontab file begins with five asterisks: * * * * * ([a_command]) >/dev/null 2>&1 The authors are gone, so I do not know their intent. What does ...
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1answer
30 views

Cron job with PHP script doesn't work properly

One of my customers have PHP script which loads cvs file. When he execute this script via WWW it works properly - logs of loaded data are stored in /var/php/CLIENT/loaded.log. But when i try to ...
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2answers
18 views

Read cron schedule from bash script

Is it possible to get the schedule for a running job? If i have this line in my crontab * * * * * /home/test/test.sh Can i read the * * * * * from test.sh, and only for that script? I hoped there ...
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0answers
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2answers
230 views

Create a cron job to run redis every 30 minutes if it is not running

I want to create a cron job that will run redis every 30 minutes if it is not already running, but I don't know what I should do. I know that the beginning should look like this */30 * * * */<some ...
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1answer
13 views

Puppet: Cannot find class cron

I'm using Puppet 3.4.3. I'm trying to use the cron type to manage cron jobs (as documented here: https://docs.puppetlabs.com/references/latest/type.html). However, any time I try and run my ...
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1answer
13 views

Aws - Ubuntu - Cron job not running

I have a aws ec2 server with ubuntu on it. I did the following to set my cron sudo crontab -e 15,45 * * * * ubuntu /usr/bin/wget -O /dev/null https://mywebsite.com/cron/ But its not running.
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3answers
850 views

Running a cronjob with different parameters each day

I am a programmer, and do not know a lot about crons, but I want to know if this is possible. Lets say I have an array [option1, option2, option3] and a script which I run in NodeJS called script.js. ...
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1answer
14 views

Cron: Execute python script, capture stdout & stderr and send via msmtp [duplicate]

I try this for almost 4 hours now, in different ways. I googled a lot, but nothing I try work as expected. I have a simple .msmtprpc file, that allows me to send mails like this: echo -e "Subject: ...
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2answers
90 views

Stop crontab from filling syslog Ubuntu 15.04

How can I prevent (certain cronjobs) from filling my syslog in Ubuntu 15.04? I have some jobs that run 4 times a minute and quickly fill up my syslog files. I've tried adding: cron.* ...
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4answers
3k views

Get cron to send html-formatted emails

I have a stats program which runs on log files via cron. The stats program can output HTML. Right now I rely on the MAIL_TO mechanism in the crontab. MAILTO=my@email.addr 55 23 * * * ...
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1answer
26 views

Crond is running twice with CentOS [closed]

I have the following issue that all of my cronjobs are running twice. When I do: ps aux | grep cron I see the following: root 1379 0.0 0.1 117296 1224 ? Ss Aug26 0:00 crond ...
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3answers
31 views

No log file output (or email with output) running Python script via cron job

I have the following cron job running a Python script which seems to install okay with no issues after creating it in Crontab and saving (this is on a server running Centos7). I'm not seeing either a ...
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3answers
2k views

Why isn't my cronjob running?

I have a cronjob in /etc/cron.d/mycron that looks like this: 0 3 * * * apache php /path/to/my/script.php In the same file there are other cronjobs begin run as root and other users (which ...
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votes
1answer
27 views

Cron every 5 minutes 8h to 20h [duplicate]

I searched for 15 minutes and to me the syntax still isn't clear... would this: */5 8,9,10,11,12,13,14,15,16,17,18,19,20 * * * run the job every 5 minutes from 8(8am) to 20 (8pm)?
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3answers
24 views

auto-attach EBS volume to a Spot instance

I need some persistent storage across spot terminations. My approach to solve the problem is Write a startup script that attaches and mounts the persistent volume Snapshot this state and register ...
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1answer
18 views

Why does crontab store my crontab under /var/spool/cron/crontabs/user instead of /etc/cron.daily

I wanted to create a crontab doing some job for me. Because my server isn't running 24/7 i decided to use anacron instead. Ok, so I took a short look into /etc/anacrontab: 1 5 cron.daily ...
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3answers
3k views

Can't run AWS CLI from CRON (credentials)

Trying to run a simple AWS CLI backup script. It loops through lines in an include file, backs those paths up to S3, and dumps output to a log file. When I run this command directly, it runs without ...
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2answers
1k views

Capturing output from a remotely executed command via SSH fails in CRON

This question is in a direct relation to this one: ssh fails to execute remote command when run from cron bash script - works from CLI I'm not able to comment on the accepted answer as I don't have ...
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5answers
1k views

Does 31 necessarily imply the end of the month in a cron job?

For cron job we know we can set time as below. # +------------ Minute (0 - 59) # | +---------- Hour (0 - 23) # | | +-------- Day of the Month (1 - 31) # | | | +------ Month (1 - 12) # | | | | +---- ...
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5answers
325 views

Making a crontab more efficient

I run a relatively simple server with a couple of web sites that I maintain. I set up a crontab to dump the mysql and zip up the PHP daily. Rotating over a week I have 7 increments of whatever has ...
2
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1answer
118 views

How do I schedule a recurring reboot in CentOS 6.7?

I've run crontab -e and added this line to crontab to reboot my machine every morning at 1am. 0 1 * * * root /sbin/shutdown -r now When crond runs I see this in my logs Aug 20 01:00:01 stc-logs ...
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1answer
22 views

shell script to grep within range inside of cron

I'm trying to create a shell script that would look for ERROR inside of /var/log/jbossas/standalone/server.log, such as following: # grep ERROR /var/log/jbossas/standalone/server.log 10:36:37,530 ...
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1answer
1k views

Compress and remove logs from jboss on linux with cron

I need to compress and remove log files after some time from serwer. I have never write scripts before. So far i have script logs.sh: #!/bin/bash LOGS=/usr/local/jboss/server/default/log/ ...
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14 views

How to launch cron job after editing crontab

I'm debugging a crontab and I would like to know if it's possible to launch a crontab right after editing. I need to know that the job will work within the cron environment. Now I'm trying to make ...
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2answers
97 views

coordinating a script to run on only one of identical load-balanced servers

I have two identically configured CentOS 5 servers (possibly more in the future). I need to run a cron job on any one of them and that it'll run only on one of them. I know about RedHat Cluster Suite ...
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1answer
29 views

running a long cron job - should I break it into smaller processes?

I have a PHP script that accesses the Amazon API at 11:00pm each night. The process takes a few hours. Will this lock up my server (haven't deployed it yet)? Is it best to run this in small batches?
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1answer
38 views

How to set Cron Job to empty cached directory

I have plain Ubuntu based server, i want to set Cron job and it will empty my website cache directory in every 24 hours, due to massive records 'rm -rf ' not work, so manually i used 'find . -name '' ...
2
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2answers
1k views

Setting 'From' header for cron email using msmtp

I've got msmtp setup on Ubuntu 10.10 so that cron can send me emails. That works like a champ, for the most part. However, emails coming to my gmail account show up as coming from (unknown sender), ...
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1answer
58 views

Why does crontab run twice while I set once everyday?

I used CentOS for Wordpress web server. I want backup media and SQL once per day, so I edit crontab as below: [john@cent ~]$ crontab -e TZ=Asia/Ho_Chi_Minh 15 3 * * * /bin/sh ...
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1answer
16 views

Python script crashes when run via Cron

I have a python script that completes exactly as expected when run manually as the root user. When I put the script into cron.daily it crashes 100% of the time. The error is a timeout error, but ...
2
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1answer
2k views

Logrotate doesn't work from cron on CentOS

I have lograotate configured on CentOS 6. It works fine when I run it manually, but with CRON it doesn't work. Cron says in its logs: "All fine, I run you command" but nothing happens. Details: cat ...
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3answers
9k views

How to configure cron job to run every 2 days at 11PM

I have a centos server and I want to run a job on it at 11PM every 2 days, how do I do that?
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0answers
14 views

Stop crontab from filling syslog Ubuntu 15.04 [duplicate]

How can I prevent (certain cronjobs) from filling my syslog in Ubuntu 15.04? I have some jobs that run 4 times a minute and quickly fill up my syslog files. I've tried adding: cron.* ...
0
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0answers
26 views

php_network_getaddresses: getaddrinfo failed: Name or service not known openshift host

I'm using openshift host for develop a custom php application, all working good in local but I've a problem to establish a connection with my database of openshift. This is the configuration file for ...
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2answers
42 views

Preventing a user from running a script that should only be run by a CRON job?

I have a contact form on my site which uses $HTTP requests instead of reloading on the form submit. It's a really awesome feature, but it also opens up some nasty doors. My contact form sends an ...
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0answers
50 views

How to apply memory limits to all cron jobs?

On a shared server (Debian Jessie), there are some memory limits (and other limits, like number of processes) that apply for a group of users, configured in /etc/security/limits.conf. It seems that ...
1
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1answer
26 views

Logrotate script not uploading to s3

I am trying to use logrotate to upload log files from my rails and nginx commands once a day. When I run the logrotate command manually the files successfully upload, but it never does it on its own. ...
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0answers
20 views

Can i run the two cron jobs for two php files each after 2 minutes difference

I have two files in my project.One file is sending the data via post method in second php file.. I want to run both files each 2 minutes difference. first file take the current data at run time and ...
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0answers
17 views

Why does python 3 script not execute via crontab? [duplicate]

There's one little problem with my crontab and python 3 script. Currently I'm on VDS with Ubuntu 14.04 installed. There're 2 scripts that need to be executed via crontab in desired time. The first ...
0
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2answers
1k views

Crontab: Authentication token expired; new one is required [duplicate]

I have a crontab job running daily as a non-root user job. Unfortunately it did stop working with the following message (in /var/log/syslog): CRON[29256]: Authentication token is no longer valid; new ...
1
vote
1answer
31 views

Solaris “crontab -e” locking via vi

I ran into an issue yesterday with locking on Solaris and crontab editing that has me wondering what the best way to protect multiple concurrent edits of the same crontab are on Solaris. I've ...
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0answers
15 views

How to setup cron on Ubuntu 14.04 with php5-fpm [duplicate]

I have php5-fpm installed on Ubuntu 14.04 and I would like to create a cronjob to execute a script every 5 minutes.. Using crontab -e I created the following: */5 * * * * /usr/sbin/php5-fpm ...
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3answers
52 views

List all running cron jobs

Is there a way to see a list of running cron jobs on my server? I would like to see the name of the file being loaded or command. Plus how long it as been running. I am on CentOS.
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crontab not executing even when cron daemon is running [duplicate]

30 1 * * * sh /export/home/omega/report_scripts_cm/parse_subscriber_cdr.sh >> /dev/null 2>&1 30 2 * * * sh /export/home/omega/report_scripts_cm/active_subscribers.sh >> /dev/null 2>&1 30 3 1 ...
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0answers
11 views

Managing lab machines via cron and dsh

I'm a developer for a research lab. Our lab has 12 Ubuntu machines for test subjects that we control from a workstation using a variety of things (dsh for opening our experiments in chrome, wakeonlan ...
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1answer
57 views

expect script running screen stops working when run by cron

I hope this question is OK for this forum. I have a device, a modem. I talk to this modem with the linux program "screen" as a terminal program. I invoke it like this "/usr/bin/screen /dev/tty6". I ...
2
votes
7answers
2k views

How to monitor cron tasks and get emails when they don't run?

I realize that when any cron has output it will email that output... what I'm trying to determine is that if I have a script scheduled for 3 AM on Tuesday and for whatever reason it either throws an ...
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11answers
14k views

Techniques to Monitor cron tasks?

Are there good techniques for monitoring cron tasks over a cluster? We're starting to use cron to launch tasks at daily intervals. A few ideas for checking out information: Add special application ...