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?
Edit: Not sure if this added context changes anything, but this is the HDD I’m using. It’s a 3.5" HDD that gets its power directly from the wall.


In short: buy a cheap ups power strip or a generous USB powebank capable to being under charge 24/7 and do not let the HDD switch off on power loss…
That is a guaranteed recepy to destroy your data and possibly the hardware as well as spinning disks don’t like abrupt shutoff and that applies to data being written on SSDs as well.
Remounting after the power resumes is the last of the issues, easily fixed by a amount/mount command with the proper fstab setup.
Do you have a USB power bank you can recommend? My external HDD requires a wall plug and I’ve never seen a USB power bank where I could plug my HDD into it.
There are DC UPSes that can supply 12V and are typically used to keep wireless routers and security cameras running for a few hours during power failures. They plug into the mains and are about the size of a 3.5" HDD.
Most USB power banks power cycle when the switch between charging/supplying/pass through mode, so if you use them for computer equipment they will lose power for a few seconds when the mains comes on or off.
Edit: DC UPSes are also much cheaper than standard ones.
You have a 3.5" based HDD (aka desktop drive). many people use 2.5" drives (laptop drives) since they get power from the PC with just usb
So that means it’s not possible for me to power my 3.5" HDD with just USB, right?
100% correct. You need a wall adapter. As many have said we all recommend a UPS (Uninterruptible Power Supply) or battery backup for your stack.
You can get the cheapest one if it’s just short term outage or brown outs (grid low volting).
Based on your wattage the capacity of the UPS will dictate how long it’ll last during an outage.