In Ubuntu Server, acpid (Advanced Configuration and Power Interface event daemon) is a background service designed to listen for hardware-level power events. When you press the physical power button on your server chassis, or close the lid on a server rack console, acpid intercepts that ACPI event and triggers a corresponding software script—usually resulting in the server initiating a graceful shutdown or entering sleep mode.
While this is standard behaviour for a consumer desktop, it is an unacceptable risk in a highly secure data centre environment. If an unauthorized technician or a clumsy visitor accidentally bumps the physical power button on your production server rack, acpid will dutifully execute a poweroff command, instantly taking your entire database offline. In enterprise environments, physical power buttons should be treated as hard emergency cuts only, and graceful software shutdowns should strictly be initiated via authenticated SSH commands. To guarantee that accidental physical button presses cannot trigger a software shutdown, you must completely disable the acpid daemon.
Disabling the Acpid Daemon via Systemd
You must stop the running service and permanently disable it from launching during the boot sequence.
- Open a Terminal session (or connect to your server via SSH).
- Stop the currently running instance of the daemon with root privileges:
sudo systemctl stop acpid - Permanently disable the service so it cannot automatically start on the next boot:
sudo systemctl disable acpid
Masking and Purging the Service
To ensure absolute system sterility and guarantee that an automated software update never accidentally resurrects the daemon, you should mask the service and remove the package entirely.
- Mask the service to create a symlink to
/dev/null, making it mathematically impossible to start:sudo systemctl mask acpid - Purge the software package and its configuration files using the APT package manager:
sudo apt-get purge acpid -y - (Optional): Remove the remaining empty configuration directories:
sudo rm -rf /etc/acpi/
Your Ubuntu Server is now completely deaf to ACPI hardware events. If someone presses the physical power button on the front of the chassis, the operating system will not react, and the server will remain perfectly online (unless they hold the button for 5 seconds to trigger a hard hardware kill). You now possess absolute, authenticated software control over the server’s power state.