My Tech-Notes

Auto Reboot Ubuntu Server Using Cron

Generated: 2025-07-15 06:22:41
System: Ubuntu (root crontab)

Example Cron Jobs

Daily Reboot at 3:30 AM

30 3 * * * /sbin/shutdown -r now

Weekly Reboot Every Sunday at 4:00 AM

0 4 * * 0 /sbin/shutdown -r now

Alternative with `reboot`

0 4 * * 0 /sbin/reboot

How To Add It

Open the root crontab:
```
sudo crontab -e
```
Add the desired line.
Save and exit.
Confirm with:
```
sudo crontab -l
```

Check Where `reboot` or `shutdown` Lives

which reboot
which shutdown

Usually: /sbin/reboot and /sbin/shutdown

Check When It Rebooted

last reboot

Tips

Use root’s crontab, otherwise you won’t have permission.
Only schedule reboots if needed (e.g., kernel updates).
Consider using unattended-upgrades for auto patching.

Example for Safe Use

0 4 * * 0 /sbin/shutdown -r now

This will reboot your Ubuntu server every Sunday at 4:00 AM.