Having a Raspberry Pi that functions as a backup device for laptops and mobile devices, large external hard drives are great. Only one drawback: they don’t ever spin down, potentially wearing them out before they should.
Looking around for open-source software that can help with spinning down my backup HDD, I came across hd-idle. Of course, it will take a wee while for it to spin up again when doing a backup. But backups tend to take quite a while anyway, so a few more seconds don’t really matter.
Since it worked really well (using a spin down after 10 minutes), I created a little systemd service for it and now my backup HDD is down and quiet most of the day. 🙂