I run my Plex server on a Raspberry Pi 4 with 4GB of RAM connected to a 2tb external hard drive.
At night the hard drive is always on even when not in use and is quite noisy. Is there a way to turn off the hard drive when no one is using the server and for it to only boot up when someone starts watching something?
Usually plex on a new system will do a complete scan of every file in your libraries this can take a few days especially if you have large libraries and because the Pi 4 is relatively low powered. Have you tried leaving it on long enough to finish (days)? After that it’s just what’s under Scheduled Tasks that runs nightly and should not take very long unless unless you add, remove or move a lot of media.