Enable cron scheduler

User tools & setup > Enable cron scheduler

cron/cronie overview

cron is a scheduling daemon that allows the system to automatically run programs and other jobs on a set schedule. In Arch systems, cronie, an implementation of cron, is used.

Notably, cronie is essential for setting up automatic system backups through timeshift. This ensures the system automatically creates snapshots on system boot, every hour, etc. at user-defined frequencies.

Note

See: cron manpage, cron wiki guide, cronie timed tasks guide

How to install cronie

To install cronie, enter:

sudo pacman -S cronie

cronie is disabled by default and must be manually enabled with:

sudo systemctl enable cronie.service

Once scheduled snapshots are configured in timeshift, the cronie scheduler will run regular jobs to automatically create snapshots.

Disable cronie

Warning

Make sure that system daemons are inactive before disabling them.

daemons such as cronie are needed for essential services. Forcibly disabling them while they are still active (and possibly running jobs) may cause the system to become unstable.

1. First, stop the cronie process with:

   systemctl stop cronie.service

2. Check that the process is inactive by running:

   systemctl status cronie.service

Terminal output with active process:

cronie.service - Command Scheduler
Loaded: loaded (/usr/lib/systemd/system/cronie.service; enabled; preset: disabled)
Active: active (running) since Day YYYY-MM-DD HH:MM:SS -timezone; 00h 00min ago
...

3. After verifying that cronie is inactive, enter:

   systemctl disable cronie.service

cron versus cronie

cron has several implementations with variations in scheduling and job management.

cronie comes with the anacron utility enabled by default, which will run backlogged jobs for systems not continuously running (ex. personal computers).

Note

See: anacron manpage