How to Permanently Disable a systemd Service on Ubuntu

Sometimes you install software that registers itself as a systemd service and starts automatically at boot. If you don’t want it running anymore, you can disable or even mask it so it never starts again. Here’s a step-by-step guide using vllm.service as an example. Step 1: Stop the Service Immediately First, stop the service if it’s currently running: sudo systemctl stop vllm.service Step 2: Disable the Service at Boot Prevent the service from starting automatically on reboot: sudo systemctl disable vllm.service This removes the symlink from the systemd startup sequence. Step 3: Mask the Service (Optional but Stronger) Masking a service ensures it cannot be started manually or by another dependency . If the unit file already exists in /etc/systemd/system/ , you’ll need to rename or remove it before masking: sudo mv /etc/systemd/system/vllm.service /etc/systemd/system/vllm.service.backup sudo systemctl daemon-reload sudo systemctl mask vllm.service Step 4: Verify the Status Check whethe