{"id":13244,"date":"2019-04-01T09:35:17","date_gmt":"2019-04-01T09:35:17","guid":{"rendered":"http:\/\/www.appservgrid.com\/paw92\/?p=13244"},"modified":"2019-04-01T09:35:17","modified_gmt":"2019-04-01T09:35:17","slug":"cron-vs-anacron-how-to-schedule-jobs-using-anacron-on-linux","status":"publish","type":"post","link":"https:\/\/www.appservgrid.com\/paw92\/index.php\/2019\/04\/01\/cron-vs-anacron-how-to-schedule-jobs-using-anacron-on-linux\/","title":{"rendered":"Cron Vs Anacron: How to Schedule Jobs Using Anacron on Linux"},"content":{"rendered":"

In this article, we will explain\u00a0cron<\/strong>\u00a0and\u00a0anacron<\/strong>\u00a0and also shows you how to setup anacron on Linux. We will as well cover a comparison of these two utilities.<\/p>\n

To\u00a0schedule a task on given or later time<\/a>, you can use the \u2018at<\/strong>\u2019 or \u2018batch<\/strong>\u2019 commands and to set up commands to run repeatedly, you can employ the\u00a0cron<\/strong>\u00a0and\u00a0anacron<\/strong>\u00a0facilities.<\/p>\n

Cron<\/a>\u00a0\u2013 is a daemon used to run scheduled tasks such as system backups, updates and many more. It is suitable for running scheduled tasks on machines that will run continuously 24X7 such as servers.<\/p>\n

The commands\/tasks are scripted into cron jobs which are scheduled in crontab files. The default system crontab file is\u00a0\/etc\/crontab<\/strong>, but each user can also create their own crontab file that can launch commands at times that the user defines.<\/p>\n

To create a personal crontab file, simply type the following:<\/p>\n

$ crontab -e\r\n<\/pre>\n
How to Setup Anacron in Linux<\/h3>\n
Anacron<\/strong>\u00a0is used to run commands periodically with a frequency defined in days. It works a little different from\u00a0cron<\/strong>; assumes that a machine will not be powered on all the time.<\/p>\n
It is appropriate for running daily, weekly, and monthly scheduled jobs normally run by cron, on machines that will not run 24-7 such as laptops and desktops machines.<\/p>\n
Assuming you have a scheduled task (such as a\u00a0backup script<\/strong>) to be run using cron every midnight, possibly when your asleep, and your desktop\/laptop is off by that time. Your backup script will not be executed.<\/p>\n
However, if you use\u00a0anacron<\/strong>, you can be assured that the next time you power on the desktop\/laptop again, the backup script will be executed.<\/p>\n
How Anacron Works in Linux<\/h3>\n
anacron jobs are listed in\u00a0\/etc\/anacrontab<\/strong>\u00a0and jobs can be scheduled using the format below (comments inside anacrontab file must start with\u00a0#<\/strong>).<\/p>\n
period   delay   job-identifier   command\r\n<\/pre>\n
From the above format:<\/p>\n