How to Auto-Run Scripts on Linux Boot: Crontab @reboot vs Systemd

1. Introduction

When a machine loses power and needs to restart many services, setting up an auto‑start script is essential. A common but inelegant method is to add a command to /etc/rc.local like the example below:

$ cat /etc/rc.local
bash /root/script/restart.sh

This works, but there are cleaner alternatives. The following sections describe two better approaches.

2. Using Crontab

Crontab supports the @reboot directive to run commands after the system boots. First, edit the crontab file:

$ crontab -e

Then add the following line:

@reboot /root/script/restart.sh

After saving, the script will automatically execute on every reboot. Additional advanced usage includes delaying execution, for example:

# Run the script 5 minutes after boot
@reboot sleep 300 && /home/wwwjobs/clean-static-cache.sh

3. Using Systemd

Create a Systemd service file named restart.service:

$ vim /lib/systemd/system/restart.service

[Unit]
Description=restart
After=default.target

[Service]
ExecStart=/root/script/restart.sh

[Install]
WantedBy=default.target

Enable and start the service with:

$ systemctl daemon-reload
$ systemctl enable restart.service

Once enabled, the associated script will run automatically at boot.

4. Reference Documents

https://www.google.com

https://tinyurl.com/6ryafefw

https://www.cyberciti.biz/faq/linux-execute-cron-job-after-system-reboot/