I’m running a Ubuntu server on my old laptop with an external HDD connected to it. The external HDD is powered independently from the laptop, as it is plugged into the wall.
During a power outage, my laptop remains operational due to its battery, but the HDD shuts down. When power is restored, my laptop does not automatically remount the HDD, and I have to reboot the system manually to access it.
Does anyone know how I can resolve this issue?


Find a used one for sale. Bonus points if it has any kind of management. Replace the battery. If at all possible, have it unmount the drive at a certain percentage.