How to set Automate Tasks on a Linux VPS Using Cron?

One of our Linux VPS customers faced an issue wherein his Virtual Machine’s system clock was running ahead of standard time. To fix this, we set a cron job to sync Virtual Machine's time with WHM server using rdate command. Cron jobs are used to schedule commands to be executed periodically on Linux/Unix like machines. Cron job utility is quite useful, especially when you are required to run commands repeatedly on specific time.

Following this tutorial, you will learn how to sync time of your server with WHM server using crone job. Before that we will explain you the usage of crone command in brief.

Crone command


Every cron command is broken into following 2 parts.

[Schedule] [Command to be executed]
For Example: */20 * * * * /command/path


In above syntax, Command is the command you would like to execute on scheduled time. Schedule part is further broken into 5 different options as follows.

minute (0 - 59)
hour (0 - 23)
day of the month (1 - 31)
month (1 - 12)
day of the week (Sunday=0 to Saturday=7)

Set crone job to sync Virtual Machine's time with WHM server


To sync Virtual Machine's system time with the WHM server time you'll need to perform the following steps after logging into a Linux machine.

  1. Connect to your Linux machine via SSH.
  2. Edit/Add crontab with the following command.

    crontab -e  //  To add/update job in crontab
  3. By issuing this command, a text editor will open where you can enter commands to be scheduled each on new line. We added command (at bottom) to sync VM system time with WHM every hour(*/60). This cron will run every hour and compare VM system time with rdate.cpanel.net. If any time difference is noticed, VM time will synced with the WHM server time.

    SHELL=/bin/bash
    HOME=/
    MAILTO=”[email protected]”
    #You can write comment like this.
    */60 * * * * rdate -s rdate.cpanel.net

Related Articles

How to remove files that are more than 100 MB inside the public_html folder in cPanel server ?

Please run the below command to find out the files that are more than 100 MB inside your cPanel...

Fix cPanel Error -The Email Account Already Exists

Sometimes, you add an email account from cPanel, and you get an error message The Email Account...

How to Install Joomla from Softaculous in cPanel?

Joomla is an open-source and a popular CMS. It is a very easy process to build a joomla template....

How to Install MySQL on CentOS 7.x?

MySQL is one of the popular database management systems. For now, MySQL is no longer within...

How to create users and groups in CentOS7?

Once the Linux system is configured, adding and removing users is one of the most basic tasks...

  • 0 Users Found This Useful

Was this answer helpful?